modules/modulecmd.tcl.in

#!@TCLSHDIR@/tclsh
#
# MODULECMD.TCL, a pure TCL implementation of the module command
# Copyright (C) 2002-2004 Mark Lakata
# Copyright (C) 2004-2017 Kent Mein
# Copyright (C) 2016-2019 Xavier Delaruelle
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

##########################################################################


#
# Some Global Variables.....
#
set g_debug 0 ;# Set to 1 to enable debugging
set error_count 0 ;# Start with 0 errors
set g_return_false 0 ;# False value is rendered if == 1
set g_autoInit 0
set g_inhibit_interp 0 ;# Modulefile interpretation disabled if == 1
set g_inhibit_errreport 0 ;# Non-critical error reporting disabled if == 1
set CSH_LIMIT 4000 ;# Workaround for commandline limits in csh
set flag_default_dir 1 ;# Report default directories
set flag_default_mf 1 ;# Report default modulefiles and version alias
set reportfd stderr ;# File descriptor to use to report messages

set g_pager {@pager@} ;# Default command to page into, empty=disable
set g_pager_opts {@pageropts@} ;# Options to pass to the pager command

set g_siteconfig @etcdir@/siteconfig.tcl ;# Site configuration
set g_tclextlib @libdir@/libtclenvmodules@SHLIB_SUFFIX@ ;# Tcl extension lib

# Source site config which can be used to define global procedures or
# settings. We first look for the global siteconfig, then if
# $MODULES_SITECONFIG is defined, source that file if it exists
proc sourceSiteConfig {} {
   lappend siteconfiglist $::g_siteconfig
   if {[info exist ::env(MODULES_SITECONFIG)]} {
      lappend siteconfiglist $::env(MODULES_SITECONFIG)
   }
   foreach siteconfig $siteconfiglist {
      if {[file readable $siteconfig]} {
         reportDebug "Source site configuration ($siteconfig)"
         if {[catch {uplevel 1 source $siteconfig} errMsg]} {
            reportErrorAndExit "Site configuration source failed\n$errMsg"
         }
         set ::g_siteconfig_loaded 1
      }
   }
}

# Used to tell if a machine is running Windows or not
proc isWin {} {
   return [expr {$::tcl_platform(platform) eq {windows}}]
}

# Get default path separator
proc getPathSeparator {} {
   if {![info exists ::g_def_separator]} {
      set ::g_def_separator [expr {[isWin] ? {;} : {:}}]
   }

   return $::g_def_separator
}

# Sub level separator to serialize a second level of info in env var
set ::g_sub1_separator &
# Sub sub level separator to serialize a third level of info in env var
set ::g_sub2_separator |

# Detect if terminal is attached to stderr message channel
proc isStderrTty {} {
   if {![info exists ::g_is_stderr_tty]} {
      set ::g_is_stderr_tty [expr {![catch {fconfigure stderr -mode}]}]
   }

   return $::g_is_stderr_tty
}

# Provide columns number for output formatting
proc getTtyColumns {} {
   if {![info exists ::g_tty_columns]} {
      # determine col number from tty capabilites
      # tty info query depends on running OS
      switch -- $::tcl_platform(os) {
         SunOS {
            catch {regexp {columns = (\d+);} [exec stty] match cols} errMsg
         }
         {Windows NT} {
            catch {regexp {Columns:\s+(\d+)} [exec mode] match cols} errMsg
         }
         default {
            catch {set cols [lindex [exec stty size] 1]} errMsg
         }
      }
      # default size if tty cols cannot be found
      set ::g_tty_columns [expr {![info exists cols] || $cols eq {0} ? 80 :\
         $cols}]
   }

   return $::g_tty_columns
}

# Get automated module handling mode
proc getAutoHandling {} {
   if {![info exists ::g_auto_handling]} {
      # default value set at configure time
      set auto_handling @autohandling@ ;# Automated modules handling if 1

      # overriden value coming from environment
      if {[info exists ::env(MODULES_AUTO_HANDLING)]} {
         # ignore non-valid values
         switch -- $::env(MODULES_AUTO_HANDLING) {
            0 - 1 {
               set auto_handling $::env(MODULES_AUTO_HANDLING)
            }
         }
      }

      # overriden value coming the command-line
      if {[info exists ::asked_auto_handling]} {
         set auto_handling $::asked_auto_handling
      }

      set ::g_auto_handling $auto_handling
      reportDebug "auto_handling set to '$auto_handling'"
   }

   return $::g_auto_handling
}

# Get force mode
proc getForce {} {
   if {![info exists ::g_force]} {
      set force 0 ;# By-pass dependency consistency

      # overriden value coming the command-line
      if {[info exists ::asked_force]} {
         set force $::asked_force
      }

      set ::g_force $force
      reportDebug "force set to '$force'"
   }

   return $::g_force
}

# Get avail in depth mode
proc getAvailInDepth {} {
   if {![info exists ::g_avail_indepth]} {
      set avail_indepth @availindepth@ ;# Search modulefiles in depth

      # overriden value coming from environment
      if {[info exists ::env(MODULES_AVAIL_INDEPTH)]} {
         # ignore non-valid values
         switch -- $::env(MODULES_AVAIL_INDEPTH) {
            0 - 1 {
               set avail_indepth $::env(MODULES_AVAIL_INDEPTH)
            }
         }
      }

      set ::g_avail_indepth $avail_indepth
      reportDebug "avail_indepth set to '$avail_indepth'"
   }

   return $::g_avail_indepth
}

# Get terminal background color kind (dark or light)
proc getTermBackground {} {
   if {![info exists ::g_term_background]} {
      set term_background @termbg@ ;# Terminal background color

      # overriden value coming from environment
      if {[info exists ::env(MODULES_TERM_BACKGROUND)]} {
         # ignore non-valid values
         switch -- $::env(MODULES_TERM_BACKGROUND) {
            dark - light {
               set term_background $::env(MODULES_TERM_BACKGROUND)
            }
         }
      }

      set ::g_term_background $term_background
      reportDebug "term_background set to '$term_background'"
   }

   return $::g_term_background
}

# Initialize Select Graphic Rendition table
proc initColors {} {
   if {![array exists ::g_colors]} {
      # overriden value coming from environment
      if {[info exists ::env(MODULES_COLORS)]} {
         set ::g_colors_list $::env(MODULES_COLORS)
         if {[catch {
            array set ::g_colors [split $::g_colors_list {:=}]
         } errMsg ]} {
            # report issue as a debug message rather warning to avoid
            # disturbing user with a warning message in the middle of a
            # useful output as this table will be initialized at first use
            reportDebug "Ignore invalid value set in MODULES_COLORS\
               ($::g_colors_list)"
            # fully clear array in case it was partially initialized
            unset -nocomplain ::g_colors
         }
      }

      # if no valid override set use default color theme for terminal
      # background color kind (light or dark)
      if {![array exists ::g_colors]} {
         set termbg [getTermBackground]
         if {$termbg eq {light}} {
            set ::g_colors_list {@lightbgcolors@}
         } else {
            set ::g_colors_list {@darkbgcolors@}
         }
         if {[catch {
            array set ::g_colors [split $::g_colors_list {:=}]
         } errMsg ]} {
            reportDebug "Ignore invalid default $termbg background colors\
               ($::g_colors_list)"
            # define an empty table if no valid value set
            array set ::g_colors {}
         }
      }

      # check each color defined and unset invalid codes
      foreach {elt col} [array get ::g_colors] {
         if {![regexp {^[\d;]+$} $col]} {
            unset ::g_colors($elt)
            reportDebug "Ignore invalid color code for '$elt' ($col)"
         }
      }

      reportDebug "colors set to '[array get ::g_colors]'"
   }
}

# Get color mode
proc getColor {} {
   if {![info exists ::g_color]} {
      set color @color@ ;# Color content automatically

      # overriden value coming from environment
      if {[info exists ::env(MODULES_COLOR)]} {
         # ignore non-valid values
         switch -- $::env(MODULES_COLOR) {
            always {
               set color 2
            }
            auto {
               set color 1
            }
            never {
               set color 0
            }
         }
      }

      # overriden value coming the command-line
      if {[info exists ::asked_color]} {
         set color $::asked_color
      }

      # disable color mode if no terminal attached except if 'always' asked
      if {$color != 0 && (![isStderrTty] || $color == 2)} {
         incr color -1
      }

      # initialize color theme if color mode enabled
      initColors

      set ::g_color $color
      reportDebug "color set to '$color'"
   }

   return $::g_color
}


# Get contact address for modulefile issue
proc getContact {} {
   if {![info exists ::g_contact]} {
      # default value, change this to your support email address...
      set contact root@localhost

      # overriden value coming from environment
      if {[info exists ::env(MODULECONTACT)]} {
         set contact $::env(MODULECONTACT)
      }

      set ::g_contact $contact
      reportDebug "contact set to '$contact'"
   }

   return $::g_contact
}

# Some directories are ignored when looking for modules.
proc getIgnoredDirs {} {
   if {![info exists ::g_ignored_dirs]} {
      set ::g_ignored_dirs {CVS RCS SCCS .svn .git .SYNC .sos}
   }
   return $::g_ignored_dirs
}

proc raiseErrorCount {} {
   incr ::error_count
}

proc renderFalse {} {
   reportDebug called.

   if {[info exists ::g_false_rendered]} {
      reportDebug {false already rendered}
   } elseif {[info exists ::g_shellType]} {
      # setup flag to render only once
      set ::g_false_rendered 1

      # render a false value most of the time through a variable assignement
      # that will be looked at in the shell module function calling
      # modulecmd.tcl to return in turns a boolean status. Except for python
      # and cmake, the value assigned to variable is also returned as the
      # entire rendering status
      switch -- $::g_shellType {
         sh - csh - fish {
            # no need to set a variable on real shells as last statement
            # result can easily be checked
            puts stdout {test 0 = 1;}
         }
         tcl {
            puts stdout {set _mlstatus 0;}
         }
         cmd {
            puts stdout {set errorlevel=1}
         }
         perl {
            puts stdout {$_mlstatus = 0;}
         }
         python {
            puts stdout {_mlstatus = False}
         }
         ruby {
            puts stdout {_mlstatus = false}
         }
         lisp {
            puts stdout {nil}
         }
         cmake {
            puts stdout {set(_mlstatus FALSE)}
         }
         r {
            puts stdout {mlstatus <- FALSE}
         }
      }
   }
}

proc renderTrue {} {
   reportDebug called.

   # render a true value most of the time through a variable assignement that
   # will be looked at in the shell module function calling modulecmd.tcl to
   # return in turns a boolean status. Except for python and cmake, the
   # value assigned to variable is also returned as the full rendering status
   switch -- $::g_shellType {
      sh - csh - fish {
         # no need to set a variable on real shells as last statement
         # result can easily be checked
         puts stdout {test 0;}
      }
      tcl {
         puts stdout {set _mlstatus 1;}
      }
      cmd {
         puts stdout {set errorlevel=0}
      }
      perl {
         puts stdout {$_mlstatus = 1;}
      }
      python {
         puts stdout {_mlstatus = True}
      }
      ruby {
         puts stdout {_mlstatus = true}
      }
      lisp {
         puts stdout {t}
      }
      cmake {
         puts stdout {set(_mlstatus TRUE)}
      }
      r {
         puts stdout {mlstatus <- TRUE}
      }
   }
}

proc renderText {text} {
   reportDebug "called ($text)."

   # render a text value most of the time through a variable assignement that
   # will be looked at in the shell module function calling modulecmd.tcl to
   # return in turns a string value.
   switch -- $::g_shellType {
      sh - csh - fish {
         foreach word $text {
            # no need to set a variable on real shells, echoing text will make
            # it available as result
            puts stdout "echo '$word';"
         }
      }
      tcl {
         puts stdout "set _mlstatus \"$text\";"
      }
      cmd {
         foreach word $text {
            puts stdout "echo $word"
         }
      }
      perl {
         puts stdout "\$_mlstatus = '$text';"
      }
      python {
         puts stdout "_mlstatus = '$text'"
      }
      ruby {
         puts stdout "_mlstatus = '$text'"
      }
      lisp {
         puts stdout "(message \"$text\")"
      }
      cmake {
         puts stdout "set(_mlstatus \"$text\")"
      }
      r {
         puts stdout "mlstatus <- '$text'"
      }
   }
}

#
# Debug, Info, Warnings and Error message handling.
#

# save message when report is not currently initialized as we do not
# know yet if debug mode is enabled or not
proc reportDebug {message {showcaller 1}} {
   # display caller name as prefix
   set prefix [expr {$showcaller && [info level] > 1 ? "[lindex [info level\
      -1] 0]: " : {}}]
   lappend ::errreport_buffer [list reportDebug $prefix$message 0]
}

# regular procedure to use once error report is initialized
proc __reportDebug {message {showcaller 1}} {
   # display active interp details if not the main one
   set prefix [currentDebugMsgPrefix]
   # display caller name as prefix
   if {$showcaller && [info level] > 1} {
      append prefix "[lindex [info level -1] 0]: "
   }
   report [sgr db "DEBUG $prefix$message"] 0 1
}

# alternative procedure used when debug is disabled
proc __reportDebugNop {args} {}

proc reportWarning {message {recordtop 0}} {
   reportError $message $recordtop WARNING wa 0
}

proc reportError {message {recordtop 0} {severity ERROR} {sgrkey er}\
   {raisecnt 1}} {
   lappend ::errreport_buffer [list reportError $message $recordtop $severity\
      $sgrkey $raisecnt]
}

proc __reportError {message {recordtop 0} {severity ERROR} {sgrkey er}\
   {raisecnt 1}} {
   # if report disabled, also disable error raise to get a coherent
   # behavior (if no message printed, no error code change)
   if {!$::g_inhibit_errreport} {
      if {$raisecnt} {
         raiseErrorCount
      }
      set message "[sgr $sgrkey $severity]: $message"
      # record message to report it later on if a record id is found
      if {[currentMsgRecordId] ne {}} {
         recordMessage $message $recordtop
      } else {
         report $message
      }
   }
}

# save message if report is not yet initialized
proc reportErrorAndExit {message} {
   lappend ::errreport_buffer [list reportErrorAndExit $message]
}

# regular procedure to use once error report is initialized
proc __reportErrorAndExit {message} {
   raiseErrorCount
   renderFalse
   error $message
}

proc reportInternalBug {message modfile} {
   # change line padding depending on output-kind
   set pad [expr {[currentMsgRecordId] ne {} ? {} : {  }}]
   reportError "$message\n${pad}In '$modfile'\n${pad}Please contact\
      <[getContact]>" 0 {Module ERROR} me
}

proc reportInfo {message {title INFO}} {
   # use reportError for conveniance but there is no error here
   reportError $message 0 $title in 0
}

# is currently active message record id at top level
proc isMsgRecordIdTop {} {
   return [expr {[llength $::g_msgRecordIdStack] eq 1}]
}

# record messages on the eventual additional module evaluations that have
# occurred during the current evaluation
proc reportModuleEval {} {
   set recid [currentMsgRecordId]
   array set contexttitle {conun {Unloading conflict} reqlo {Loading\
      requirement} depre {Reloading dependent} depun {Unloading dependent}\
      urequn {Unloading useless requirement} unmo {Unloading module} lomo\
      {Loading module}}

   if {[info exists ::g_moduleEval($recid)]} {
      foreach contextevallist $::g_moduleEval($recid) {
         set modlist [lassign $contextevallist context]
         # skip context with no description title
         if {[info exists contexttitle($context)]} {
            reportInfo [join $modlist] $contexttitle($context)
         }
      }
      # purge list in case same evaluation is re-done afterward
      unset ::g_moduleEval($recid)
   }
}

# render messages related to current record id under an header block
proc reportMsgRecord {header} {
   set recid [currentMsgRecordId]
   if {[info exists ::g_msgRecord($recid)]} {
      set tty_cols [getTtyColumns]
      set padding {  }

      set dispmsg $header
      foreach msg $::g_msgRecord($recid) {
         # split lines if too large for terminal
         set first 1
         set max_idx [expr {$tty_cols - [string length $padding]}]
         set linelist [list]
         foreach line [split $msg \n] {
            set lineadd {}
            while {$lineadd ne $line} {
               # no split if no whitespace found to slice
               if {[string length $line] > $max_idx && [set cut_idx [string\
                  last { } $line $max_idx]] != -1} {
                  set lineadd [string range $line 0 [expr {$cut_idx-1}]]
                  set line [string range $line [expr {$cut_idx+1}] end]
               } else {
                  set lineadd $line
               }
               lappend linelist $lineadd
               if {$first} {
                  set first 0
                  incr max_idx -[string length $padding]
               }
            }
         }

         # display each line
         set first 1
         foreach line $linelist {
            append dispmsg \n
            if {$first} {
               set first 0
            } else {
               append dispmsg $padding
            }
            append dispmsg $padding$line
         }
      }
      reportSeparateNextContent
      report $dispmsg
      reportSeparateNextContent

      # purge message list in case same evaluation is re-done afterward
      unset ::g_msgRecord($recid)
   }
}

# separate next content produced if any
proc reportSeparateNextContent {} {
   lappend ::errreport_buffer [list reportSeparateNextContent]
}

# regular procedure to use once error report is initialized
proc __reportSeparateNextContent {} {
   # hold or apply
   if {[isReportHeld]} {
      lappend ::g_holdReport([currentReportHoldId]) [list\
         reportSeparateNextContent]
   } else {
      set ::g_report_sep_next 1
   }
}

# save message for block rendering
proc recordMessage {message {recordtop 0}} {
   lappend ::g_msgRecord([expr {$recordtop ? [topMsgRecordId] :\
      [currentMsgRecordId]}]) $message
}

# Select Graphic Rendition of a string with passed sgr key (if color enabled)
proc sgr {sgrkey str} {
   if {[getColor] && [info exists ::g_colors($sgrkey)]} {
      set sgrset $::g_colors($sgrkey)
      # if render bold or faint just reset that attribute, not all
      if {$sgrset == 1 || $sgrset == 2} {
         set sgrreset 22
      } else {
         set sgrreset 0
      }
      set str "\033\[${sgrset}m$str\033\[${sgrreset}m"
   }
   return $str
}

# save message if report is not yet initialized
proc report {message {nonewline 0} {immed 0}} {
   lappend ::errreport_buffer [list report $message $nonewline $immed]
}

# regular procedure to use once error report is initialized
proc __report {message {nonewline 0} {immed 0}} {
   # hold or print output
   if {!$immed && [isReportHeld]} {
      lappend ::g_holdReport([currentReportHoldId]) [list report $message\
         $nonewline]
   } else {
      if {![info exists ::g_already_report]} {
         set ::g_already_report 1
         # start pager at first call and only if enabled
         if {$::start_pager} {
            startPager
         }
      # produce blank line prior message if asked to
      } elseif {[info exists ::g_report_sep_next]} {
         unset ::g_report_sep_next
         report {}
      }

      # protect from issue with fd, just ignore it
      catch {
         if {$nonewline} {
            puts -nonewline $::reportfd $message
         } else {
            puts $::reportfd $message
         }
      }
   }
}

# report error the correct way depending of its type
proc reportIssue {issuetype issuemsg {issuefile {}}} {
   switch -- $issuetype {
      invalid {
         reportInternalBug $issuemsg $issuefile
      }
      default {
         reportError $issuemsg
      }
   }
}

# report defined command (used in display evaluation mode)
proc reportCmd {cmd args} {
   set extratab [expr {[string length $cmd] < 8 ? "\t" : {}}]
   # only brace empty arguments or those containing whitespace
   set cmdargs {}
   foreach cmdarg $args {
      if {$cmdargs ne {}} {
         append cmdargs { }
      }
      append cmdargs [expr {$cmdarg eq {} || [string first { } $cmdarg] > -1\
         ? "{$cmdarg}" : $cmdarg}]
   }
   report [sgr cm $cmd]$extratab\t$cmdargs

   # empty string returns if command result is another command input
   return {}
}

# report defined command (called as an execution trace)
proc reportCmdTrace {cmdstring args} {
   eval reportCmd $cmdstring
}

proc reportVersion {} {
   report {Modules Release @MODULES_RELEASE@@MODULES_BUILD@\
      (@MODULES_BUILD_DATE@)}
}

# disable error reporting (non-critical report only) unless debug enabled
proc inhibitErrorReport {} {
   if {!$::g_debug} {
      set ::g_inhibit_errreport 1
   }
}

proc reenableErrorReport {} {
   set ::g_inhibit_errreport 0
}

proc isErrorReportInhibited {} {
   return $::g_inhibit_errreport
}

# init error report and output buffered messages
proc initErrorReport {} {
   # ensure init is done only once
   if {![info exists ::g_init_error_report]} {
      set ::g_init_error_report 1
      # determine message paging configuration and enablement
      initPager

      # ask for color init now as debug mode has already fire lines to render
      # and we want them to be reported first (not the color init lines)
      if {$::g_debug} {
         getColor
      }

      # replace report procedures used to bufferize messages until error
      # report being initialized by regular report procedures
      rename ::reportDebug {}
      if {$::g_debug} {
         rename ::__reportDebug ::reportDebug
      } else {
         # set a disabled version if debug is disabled
         rename ::__reportDebugNop ::reportDebug
      }
      rename ::reportError {}
      rename ::__reportError ::reportError
      rename ::reportErrorAndExit {}
      rename ::__reportErrorAndExit ::reportErrorAndExit
      rename ::reportSeparateNextContent {}
      rename ::__reportSeparateNextContent ::reportSeparateNextContent
      rename ::report {}
      rename ::__report ::report

      # now error report is init output every message saved in buffer
      foreach errreport $::errreport_buffer {
         eval $errreport
      }
   }
}

# drop or report held messages
proc releaseHeldReport {args} {
   foreach {holdid action} $args {
      if {[info exists ::g_holdReport($holdid)]} {
         if {$action eq {report}} {
            foreach repcall $::g_holdReport($holdid) {
               eval $repcall
            }
         }
         unset ::g_holdReport($holdid)
      }
   }
}

# exit in a clean manner by closing interaction with external components
proc cleanupAndExit {code} {
   # close pager if enabled
   if {$::reportfd ne {stderr}} {
      catch {flush $::reportfd}
      catch {close $::reportfd}
   }

   exit $code
}

# init configuration for output paging to prepare for startup
proc initPager {} {
   # default pager enablement depends of pager command value
   if {$::g_pager eq {} || [file tail $::g_pager] eq {cat}} {
      set ::use_pager 0
      set init_use_pager 0
   } else {
      set ::use_pager 1
      set init_use_pager 1
   }

   if {[info exists ::env(MODULES_PAGER)]} {
      if {$::env(MODULES_PAGER) ne {}} {
         # MODULES_PAGER env variable set means pager should be enabled
         if {!$::use_pager} {
            set ::use_pager 1
         }
         # fetch pager command and option
         set ::g_pager [lindex $::env(MODULES_PAGER) 0]
         set ::g_pager_opts [lrange $::env(MODULES_PAGER) 1 end]

      # variable defined empty means no-pager
      } else {
         set ::use_pager 0
         set ::g_pager {}
         set ::g_pager_opts {}
      }

      reportDebug "configure pager from MODULES_PAGER variable\
         (use_pager=$::use_pager, cmd='$::g_pager', opts='$::g_pager_opts')"
   }

   # paging may have been enabled or disabled from the command-line
   if {[info exists ::asked_pager]} {
      # enable from command-line only if it is enabled in script config
      if {$::asked_pager && !$::use_pager && $init_use_pager} {
         set ::use_pager 1
      } elseif {!$::asked_pager && $::use_pager} {
         set ::use_pager 0
      }
      set asked $::asked_pager
   } else {
      set asked -
   }

   # empty or 'cat' pager command means no-pager
   if {$::use_pager && ($::g_pager eq {} || [file tail $::g_pager] eq\
      {cat})} {
      set ::use_pager 0
   }

   # some module command may also turn off pager
   if {$::command eq {clear}} {
      set ::use_pager 0
   }

   # start paging if enabled and if error stream is attached to a terminal
   set is_tty [isStderrTty]
   if {$is_tty && $::use_pager} {
      reportDebug "start pager (asked_pager=$asked, cmd='$::g_pager',\
         opts='$::g_pager_opts')"
      set ::start_pager 1
   } else {
      reportDebug "no pager start (is_tty=$is_tty, mod_cmd='$::command',\
         use_pager=$::use_pager, asked_pager=$asked, cmd='$::g_pager',\
         opts='$::g_pager_opts')"
      set ::start_pager 0
   }
}

# start pager pipe process with defined configuration
proc startPager {} {
   if {[catch {
      set ::reportfd [open "|$::g_pager $::g_pager_opts >@stderr 2>@stderr" w]
      fconfigure $::reportfd -buffering line -blocking 1 -buffersize 65536
   } errMsg]} {
      reportWarning $errMsg
   }
}

# helper procedures to format various messages
proc getHintUnFirstMsg {modlist} {
   return "HINT: Might try \"module unload [join $modlist]\" first."
}

proc getHintLoFirstMsg {modlist} {
   if {[llength $modlist] > 1} {
      set oneof {at least one of }
      set mod modules
   } else {
      set oneof {}
      set mod module
   }
   return "HINT: ${oneof}the following $mod must be loaded first: $modlist"
}

proc getErrConflictMsg {mod conlist} {
   return "$mod cannot be loaded due to a conflict.\n[getHintUnFirstMsg\
      $conlist]"
}

proc getErrPrereqMsg {mod prelist {load 1}} {
   lassign [if {$load} {list {} missing [getHintLoFirstMsg $prelist]}\
      {list un a [getHintUnFirstMsg $prelist]}] un mis hintmsg
   return "$mod cannot be ${un}loaded due to $mis prereq.\n$hintmsg"
}

proc getErrReqLoMsg {prelist} {
   return "Load of requirement [join $prelist { or }] failed"
}

proc getReqNotLoadedMsg {prelist} {
   return "Requirement [join $prelist { or }] is not loaded"
}

proc getDepLoadedMsg {prelist} {
   set is [expr {[llength $prelist] > 1 ? {are} : {is}}]
   return "Dependent [join $prelist { and }] $is loaded"
}

proc getErrConUnMsg {conlist} {
   return "Unload of conflicting [join $conlist { and }] failed"
}

proc getConIsLoadedMsg {conlist {loading 0}} {
   set is [expr {[llength $conlist] > 1 ? {are} : {is}}]
   set loaded [expr {$loading ? {loading} : {loaded}}]
   return "Conflicting [join $conlist { and }] $is $loaded"
}

########################################################################
# Use a slave TCL interpreter to execute modulefiles
#

# dummy proc to disable modulefile commands on some evaluation modes
proc nop {args} {}

# dummy proc for commands available on other Modules flavor but not here
proc nimp {cmd args} {
   reportWarning "'$cmd' command not implemented"
}

proc get-env {var {valifunset {}}} {
   # return current value if exists and not cleared
   if {[info exists ::env($var)] && ![info exists ::g_clearedEnvVars($var)]} {
      return $::env($var)
   } else {
      return $valifunset
   }
}

proc set-env {var val} {
   set mode [currentMode]
   reportDebug "$var=$val"
   set ::env($var) $val

   # variable is not cleared anymore if set again
   if {[info exists ::g_clearedEnvVars($var)]} {
      unset ::g_clearedEnvVars($var)
   }

   # propagate variable setup to shell environment on load and unload mode
   if {$mode eq {load} || $mode eq {unload}} {
      set ::g_stateEnvVars($var) new
   }
}

proc reset-to-unset-env {var {val {}}} {
   set ::env($var) $val
   # set var as cleared if val is empty
   if {$val eq {}} {
      set ::g_clearedEnvVars($var) 1
   }
}

proc unset-env {var {internal 0} {val {}}} {
   set mode [currentMode]
   reportDebug "$var (internal=$internal, val=$val)"

   # clear value instead of unset it not to break variable later reference
   # in modulefile. clear whether variable set or not to get a later usage
   # consistent behavior whatever env is setup
   if {!$internal} {
      reset-to-unset-env $var $val
   # internal variables (like ref counter var) are purely unset if they exists
   } elseif {[info exists ::env($var)]} {
      unset ::env($var)
      set intwasset 1
   }

   # propagate deletion in any case if variable is public and for internal
   # one only if variable was set
   if {($mode eq {load} || $mode eq {unload}) && (!$internal ||\
      [info exists intwasset])} {
      set ::g_stateEnvVars($var) del
   }
}

# Initialize list of interp alias commands to define for given evaluation mode
proc initModfileModeAliases {mode aliasesVN aliasesPassArgVN tracesVN} {
   global g_modfilePerModeAliases
   upvar #0 $aliasesVN aliases
   upvar #0 $aliasesPassArgVN aliasesPassArg
   upvar #0 $tracesVN traces

   if {![info exists g_modfilePerModeAliases]} {
      set ::g_modfileBaseAliases [list getenv getenv is-loaded is-loaded\
         is-saved is-saved is-used is-used is-avail is-avail uname uname\
         module-info module-info exit exitModfileCmd reportCmdTrace\
         reportCmdTrace reportInternalBug reportInternalBug reportWarning\
         reportWarning reportError reportError raiseErrorCount\
         raiseErrorCount report report isWin isWin puts putsModfileCmd\
         readModuleContent readModuleContent]

      # list of alias commands whose target procedure is adapted according to
      # the evaluation mode
      set ::g_modfileEvalModes {load unload display help test whatis}
      array set g_modfilePerModeAliases {
append-path    {append-path    remove-path    append-path    append-path    append-path    edit-path-wh  }
chdir          {chdir          nop            reportCmd      nop            nop            nop           }
conflict       {conflict       nop            reportCmd      nop            nop            nop           }
module         {module         module         reportCmd      nop            nop            nop           }
module-alias   {module-alias   module-alias   module-alias   module-alias   module-alias   module-alias  }
module-log     {nimp           nimp           reportCmd      nop            nop            nop           }
module-trace   {nimp           nimp           reportCmd      nop            nop            nop           }
module-user    {nimp           nimp           reportCmd      nop            nop            nop           }
module-verbosity {nimp         nimp           reportCmd      nop            nop            nop           }
module-version {module-version module-version module-version module-version module-version module-version}
module-virtual {module-virtual module-virtual module-virtual module-virtual module-virtual module-virtual}
module-whatis  {nop            nop            reportCmd      nop            nop            module-whatis }
prepend-path   {prepend-path   remove-path    prepend-path   prepend-path   prepend-path   edit-path-wh  }
prereq         {prereq         nop            reportCmd      nop            nop            nop           }
remove-path    {remove-path    remove-path-un remove-path    remove-path    remove-path    edit-path-wh  }
set-alias      {set-alias      set-alias-un   reportCmd      nop            nop            nop           }
set-function   {set-function   set-function-un reportCmd     nop            nop            nop           }
setenv         {setenv         setenv-un      setenv         setenv         setenv         setenv-wh     }
system         {system         system         reportCmd      nop            nop            nop           }
unset-alias    {unset-alias    nop            reportCmd      nop            nop            nop           }
unset-function {unset-function nop            reportCmd      nop            nop            nop           }
unsetenv       {unsetenv       unsetenv-un    unsetenv       unsetenv       unsetenv       setenv-wh     }
x-resource     {x-resource     x-resource     reportCmd      nop            nop            nop           }
      }
   }

   # alias commands where interpreter ref should be passed as argument
   array set aliasesPassArg [list puts __itrp__]

   # initialize list with all commands not dependent of the evaluation mode
   array set aliases $::g_modfileBaseAliases

   # add alias commands whose target command vary depending on the eval mode
   set modeidx [lsearch -exact $::g_modfileEvalModes $mode]
   foreach alias [array names g_modfilePerModeAliases] {
      set aliastarget [set aliases($alias) [lindex\
         $g_modfilePerModeAliases($alias) $modeidx]]
      # some target procedures need command name as first arg
      if {$aliastarget eq {reportCmd} || $aliastarget eq {nimp}} {
         set aliasesPassArg($alias) $alias
      # associate a trace command if per-mode alias command is not reportCmd
      # in display mode
      } elseif {$mode eq {display}} {
         set traces($alias) reportCmdTrace
      }
   }
}

proc execute-modulefile {modfile modname modspec {must_have_cookie 1}} {
   pushModuleFile $modfile
   pushModuleName $modname
   pushSpecifiedName $modspec
   set mode [currentMode]
   pushDebugMsgPrefix [getEvalModuleStackDepth] $mode $modname

   # skip modulefile if interpretation has been inhibited
   if {$::g_inhibit_interp} {
      reportDebug "skipping $modfile"
      return 1
   }

   reportDebug "sourcing $modfile"

   if {![info exists ::g_modfileUntrackVars]} {
      # list variable that should not be tracked for saving
      array set ::g_modfileUntrackVars [list ModulesCurrentModulefile 1\
         must_have_cookie 1 modcontent 1 env 1]

      # commands that should be renamed before aliases setup
      array set ::g_modfileRenameCmds [list puts _puts]
   }
   # dedicate an interpreter per mode and per level of interpretation to have
   # a dedicated interpreter in case of cascaded multi-mode interpretations
   set itrp __modfile_${mode}_[getEvalModuleStackDepth]

   # evaluation mode-specific configuration
   set dumpCommandsVN g_modfile${mode}Commands
   set aliasesVN g_modfile${mode}Aliases
   set aliasesPassArgVN g_modfile${mode}AliasesPassArg
   set tracesVN g_modfile${mode}Traces
   if {![info exists ::$aliasesVN]} {
      initModfileModeAliases $mode $aliasesVN $aliasesPassArgVN $tracesVN
   }

   # create modulefile interpreter at first interpretation
   if {![interp exists $itrp]} {
      reportDebug "creating interp $itrp"
      interp create $itrp

      # dump initial interpreter state to restore it before each modulefile
      # interpretation. use same dump state for all modes/levels
      if {![info exists ::g_modfileVars]} {
         dumpInterpState $itrp g_modfileVars g_modfileArrayVars\
            g_modfileUntrackVars g_modfileProcs
      }

      # interp has just been created
      set fresh 1
   } else {
      set fresh 0
   }

   # reset interp state command before each interpretation
   resetInterpState $itrp $fresh g_modfileVars g_modfileArrayVars\
      g_modfileUntrackVars g_modfileProcs $aliasesVN $aliasesPassArgVN\
      $tracesVN g_modfileRenameCmds $dumpCommandsVN

   # reset modulefile-specific variable before each interpretation
   interp eval $itrp set ::ModulesCurrentModulefile $modfile
   interp eval $itrp set must_have_cookie $must_have_cookie

   set errorVal [interp eval $itrp {
      set modcontent [readModuleContent $::ModulesCurrentModulefile 1\
         $must_have_cookie]
      if {$modcontent eq {}} {
         return 1
      }
      info script $::ModulesCurrentModulefile
      # eval then call for specific proc depending mode under same catch
      set sourceFailed [catch {
         eval $modcontent
         switch -- [module-info mode] {
            help {
               if {[info procs ModulesHelp] eq {ModulesHelp}} {
                  ModulesHelp
               } else {
                  reportWarning "Unable to find ModulesHelp in\
                     $::ModulesCurrentModulefile."
               }
            }
            display {
               if {[info procs ModulesDisplay] eq {ModulesDisplay}} {
                  ModulesDisplay
               }
            }
            test {
               if {[info procs ModulesTest] eq {ModulesTest}} {
                  if {[string is true -strict [ModulesTest]]} {
                     report {Test result: PASS}
                  } else {
                     report {Test result: FAIL}
                     raiseErrorCount
                  }
               } else {
                  reportWarning "Unable to find ModulesTest in\
                     $::ModulesCurrentModulefile."
               }
            }
         }
      } errorMsg]
      if {$sourceFailed} {
         # no error in case of "continue" command
         # catch continue even if called outside of a loop
         if {$errorMsg eq {invoked "continue" outside of a loop}\
            || $sourceFailed == 4} {
            unset errorMsg
            return 0
         # catch break even if called outside of a loop
         } elseif {$errorMsg eq {invoked "break" outside of a loop}\
            || ($errorMsg eq {} && (![info exists ::errorInfo]\
            || $::errorInfo eq {}))} {
            raiseErrorCount
            unset errorMsg
            return 1
         } elseif {$errorMsg eq {SUB_FAILED}} {
            # error counter and message already handled, just return error
            return 1
         } elseif {[string range $errorMsg 0 12] eq {GLOBALERRTOP }} {
            reportError [string range $errorMsg 13 end] 1
            return 1
         } elseif {[string range $errorMsg 0 9] eq {GLOBALERR }} {
            reportError [string range $errorMsg 10 end]
            return 1
         } else {
            reportInternalBug $errorMsg $::ModulesCurrentModulefile
            return 1
         }
      } else {
         unset errorMsg
         return 0
      }
   }]

   reportDebug "exiting $modfile"
   popDebugMsgPrefix
   popSpecifiedName
   popModuleName
   popModuleFile

   return $errorVal
}

# Smaller subset than main module load... This function runs modulerc and
# .version files
proc execute-modulerc {modfile modname modspec} {
   pushModuleFile $modfile
   # push name to be found by module-alias and version
   pushModuleName $modname
   pushSpecifiedName $modspec
   set ::ModulesVersion {}
   pushDebugMsgPrefix [getEvalModuleStackDepth] $modname

   if {![info exists ::g_modrcUntrackVars]} {
      # list variable that should not be tracked for saving
      array set ::g_modrcUntrackVars [list ModulesCurrentModulefile 1\
         ModulesVersion 1 modcontent 1 env 1]

      # commands that should be renamed before aliases setup
      array set ::g_modrcRenameCmds [list]

      # list interpreter alias commands to define
      array set ::g_modrcAliases [list uname uname system system chdir\
         nop is-loaded is-loaded module-version module-version module-alias\
         module-alias module-virtual module-virtual module nop module-info\
         module-info module-trace nop module-verbosity nop module-user nop\
         module-log nop reportInternalBug reportInternalBug setModulesVersion\
         setModulesVersion readModuleContent readModuleContent]

      # alias commands where an argument should be passed
      array set ::g_modrcAliasesPassArg [list]

      # trace commands that should be associated to aliases
      array set ::g_modrcAliasesTraces [list]
   }

   # dedicate an interpreter per level of interpretation to have in case of
   # cascaded interpretations a specific interpreter per level
   set itrp __modrc_[getEvalModuleStackDepth]

   reportDebug "sourcing $modfile"
   # create modulerc interpreter at first interpretation
   if {![interp exists $itrp]} {
      reportDebug "creating interp $itrp"
      interp create $itrp

      # dump initial interpreter state to restore it before each modulerc
      # interpreation. use same dump state for all levels
      if {![info exists ::g_modrcVars]} {
         dumpInterpState $itrp g_modrcVars g_modrcArrayVars\
            g_modrcUntrackVars g_modrcProcs
      }

      # interp has just been created
      set fresh 1
   } else {
      set fresh 0
   }

   # reset interp state command before each interpretation
   resetInterpState $itrp $fresh g_modrcVars g_modrcArrayVars\
      g_modrcUntrackVars g_modrcProcs g_modrcAliases g_modrcAliasesPassArg\
      g_modrcAliasesTraces g_modrcRenameCmds g_modrcCommands

   interp eval $itrp set ::ModulesCurrentModulefile $modfile
   interp eval $itrp {set ::ModulesVersion {}}

   set errorVal [interp eval $itrp {
      set modcontent [readModuleContent $::ModulesCurrentModulefile]
      if {$modcontent eq {}} {
         # simply skip rc file, no exit on error here
         return 1
      }
      info script $::ModulesCurrentModulefile
      if [catch {eval $modcontent} errorMsg] {
         reportInternalBug $errorMsg $::ModulesCurrentModulefile
         return 1
      } else {
         # pass ModulesVersion value to master interp
         if {[info exists ::ModulesVersion]} {
            setModulesVersion $::ModulesVersion
         }
         return 0
      }
   }]

   # default version set via ModulesVersion variable in .version file
   # override previously defined default version for modname
   lassign [getModuleNameVersion] mod modname modversion
   if {$modversion eq {.version} && $::ModulesVersion ne {}} {
      # ModulesVersion should target an element in current directory
      if {[string first / $::ModulesVersion] == -1} {
         setModuleResolution $modname/default $modname/$::ModulesVersion\
            default
      } else {
         reportError "Invalid ModulesVersion '$::ModulesVersion' defined"
      }
   }

   popDebugMsgPrefix
   popSpecifiedName
   popModuleName
   popModuleFile

   return $::ModulesVersion
}

# Save list of the defined procedure and the global variables with their
# associated values set in slave interpreter passed as argument. Global
# structures are used to save these information and the name of these
# structures are provided as argument.
proc dumpInterpState {itrp dumpVarsVN dumpArrayVarsVN untrackVarsVN\
   dumpProcsVN} {
   upvar #0 $dumpVarsVN dumpVars
   upvar #0 $dumpArrayVarsVN dumpArrayVars
   upvar #0 $untrackVarsVN untrackVars
   upvar #0 $dumpProcsVN dumpProcs

   regexp {^__[a-z]+} $itrp itrpkind
   # save name and value for any other global variables
   foreach var [$itrp eval {info globals}] {
      if {![info exists untrackVars($var)]} {
         reportDebug "saving for $itrpkind var $var"
         if {[$itrp eval array exists ::$var]} {
            set dumpVars($var) [$itrp eval array get ::$var]
            set dumpArrayVars($var) 1
         } else {
            set dumpVars($var) [$itrp eval set ::$var]
         }
      }
   }

   # save name of every defined procedures
   foreach var [$itrp eval {info procs}] {
      set dumpProcs($var) 1
   }
   reportDebug "saving for $itrpkind proc list [array names dumpProcs]"
}

# Define commands to be known by slave interpreter.
proc initInterpCommands {itrp fresh aliasesVN aliasesPassArgVN tracesVN\
   renameCmdsVN} {
   upvar #0 $aliasesVN aliases
   upvar #0 $aliasesPassArgVN aliasesPassArg
   upvar #0 $tracesVN traces
   upvar #0 $renameCmdsVN renameCmds

   # rename some commands on freshly created interp before aliases defined
   # below overwrite them
   if {$fresh} {
      foreach cmd [array names renameCmds] {
         $itrp eval rename $cmd $renameCmds($cmd)
      }
   }

   # set interpreter alias commands each time to guaranty them being
   # defined and not overridden by modulefile or modulerc content
   foreach alias [array names aliases] {
      if {[info exists aliasesPassArg($alias)]} {
         set aliasarg $aliasesPassArg($alias)
         # pass current itrp reference on special keyword
         if {$aliasarg eq {__itrp__}} {
            set aliasarg $itrp
         }
         interp alias $itrp $alias {} $aliases($alias) $aliasarg
      } else {
         interp alias $itrp $alias {} $aliases($alias)
      }
   }

   foreach alias [array names traces] {
      interp eval $itrp [list trace add execution $alias leave\
         $traces($alias)]
   }
}

# Restore initial setup of slave interpreter passed as argument based on
# global structure previously filled with initial list of defined procedure
# and values of global variable.
proc resetInterpState {itrp fresh dumpVarsVN dumpArrayVarsVN untrackVarsVN\
   dumpProcsVN aliasesVN aliasesPassArgVN tracesVN renameCmdsVN\
   dumpCommandsVN} {
   upvar #0 $dumpVarsVN dumpVars
   upvar #0 $dumpArrayVarsVN dumpArrayVars
   upvar #0 $untrackVarsVN untrackVars
   upvar #0 $dumpProcsVN dumpProcs
   upvar #0 $dumpCommandsVN dumpCommands

   # look at list of defined procedures and delete those not part of the
   # initial state list. do not check if they have been altered as no vital
   # procedures lied there. note that if a Tcl command has been overridden
   # by a proc, it will be removed here and command will also disappear
   foreach var [$itrp eval {info procs}] {
      if {![info exists dumpProcs($var)]} {
         reportDebug "removing on $itrp proc $var"
         $itrp eval [list rename $var {}]
      }
   }

   # rename some commands and set aliases on interpreter
   initInterpCommands $itrp $fresh $aliasesVN $aliasesPassArgVN $tracesVN\
      $renameCmdsVN

   # dump interpreter command list here on first time as aliases should be
   # set prior to be found on this list for correct match
   if {![info exists dumpCommands]} {
      set dumpCommands [$itrp eval {info commands}]
      reportDebug "saving for $itrp command list $dumpCommands"
   # if current interpreter command list does not match initial list it
   # means that at least one command has been altered so we need to recreate
   # interpreter to guaranty proper functioning
   } elseif {$dumpCommands ne [$itrp eval {info commands}]} {
      reportDebug "missing command(s), recreating interp $itrp"
      interp delete $itrp
      interp create $itrp
      initInterpCommands $itrp 1 $aliasesVN $aliasesPassArgVN $tracesVN\
         $renameCmdsVN
   }

   # check every global variables currently set and correct them to restore
   # initial interpreter state. work on variables at the very end to ensure
   # procedures and commands are correctly defined
   foreach var [$itrp eval {info globals}] {
      if {![info exists untrackVars($var)]} {
         if {![info exists dumpVars($var)]} {
            reportDebug "removing on $itrp var $var"
            $itrp eval unset ::$var
         } elseif {![info exists dumpArrayVars($var)]} {
            if {$dumpVars($var) ne [$itrp eval set ::$var]} {
               reportDebug "restoring on $itrp var $var"
               if {[llength $dumpVars($var)] > 1} {
                  # restore value as list
                  $itrp eval set ::$var [list $dumpVars($var)]
               } else {
                  # brace value to be able to restore empty string
                  $itrp eval set ::$var "{$dumpVars($var)}"
               }
            }
         } else {
            if {$dumpVars($var) ne [$itrp eval array get ::$var]} {
               reportDebug "restoring on $itrp var $var"
               $itrp eval array set ::$var [list $dumpVars($var)]
            }
         }
      }
   }
}

########################################################################
# commands run from inside a module file
#

proc module-info {what {more {}}} {
   set mode [currentMode]

   reportDebug "$what $more"

   switch -- $what {
      mode {
         if {$more ne {}} {
            set command [currentCommandName]
            return [expr {$mode eq $more || ($more eq {remove} && $mode eq \
               {unload}) || ($more eq {switch} && $command eq {switch})}]
         } else {
            return $mode
         }
      }
      command {
         set command [currentCommandName]
         if {$more eq {}} {
            return $command
         } else {
            return [expr {$command eq $more}]
         }
      }
      name {
         return [currentModuleName]
      }
      specified {
         return [currentSpecifiedName]
      }
      shell {
         if {$more ne {}} {
            return [expr {$::g_shell eq $more}]
         } else {
            return $::g_shell
         }
      }
      flags {
         # C-version specific option, not relevant for Tcl-version but return
         # a zero integer value to avoid breaking modulefiles using it
         return 0
      }
      shelltype {
         if {$more ne {}} {
            return [expr {$::g_shellType eq $more}]
         } else {
            return $::g_shellType
         }
      }
      user {
         # C-version specific option, not relevant for Tcl-version but return
         # an empty value or false to avoid breaking modulefiles using it
         if {$more ne {}} {
            return 0
         } else {
            return {}
         }
      }
      alias {
         set ret [resolveModuleVersionOrAlias $more]
         if {$ret ne $more} {
            return $ret
         } else {
            return {}
         }
      }
      trace {
         return {}
      }
      tracepat {
         return {}
      }
      type {
         return Tcl
      }
      symbols {
         lassign [getModuleNameVersion $more 1] mod modname modversion
         set tag_list [getVersAliasList $mod]
         # if querying special symbol "default" but nothing found registered
         # on it, look at symbol registered on bare module name in case there
         # are symbols registered on it but no default symbol set yet to link
         # to them
         if {[llength $tag_list] == 0 && $modversion eq {default}} {
            set tag_list [getVersAliasList $modname]
         }
         return [join $tag_list :]
      }
      version {
         lassign [getModuleNameVersion $more 1] mod
         return [resolveModuleVersionOrAlias $mod]
      }
      loaded {
         lassign [getModuleNameVersion $more 1] mod
         return [getLoadedMatchingName $mod returnall]
      }
      default {
         error "module-info $what not supported"
         return {}
      }
   }
}

proc module-whatis {args} {
   set message [join $args]
   reportDebug $message
   lappend ::g_whatis $message

   return {}
}

# convert environment variable references in string to their values
# every local variable is prefixed by '0' to ensure they will not be
# overwritten through variable reference resolution process
proc resolvStringWithEnv {0str} {
   # fetch variable references in string
   set 0match_list [regexp -all -inline {\$[{]?([A-Za-z_][A-Za-z0-9_]*)[}]?}\
      ${0str}]
   if {[llength ${0match_list}] > 0} {
      # put in local scope every environment variable referred in string
      for {set 0i 1} {${0i} < [llength ${0match_list}]} {incr 0i 2} {
         set 0varname [lindex ${0match_list} ${0i}]
         if {![info exists ${0varname}]} {
            set ${0varname} [get-env ${0varname}]
         }
      }
      # resolv variable reference with values (now in local scope)
      set 0res [subst -nobackslashes -nocommands ${0str}]
   } else {
      set 0res ${0str}
   }

   reportDebug "'${0str}' resolved to '${0res}'"

   return ${0res}
}

# deduce modulepath from modulefile and module name
proc getModulepathFromModuleName {modfile modname} {
   return [string range $modfile 0 end-[string length /$modname]]
}

# deduce module name from modulefile and modulepath
proc getModuleNameFromModulepath {modfile modpath} {
   return [string range $modfile [string length $modpath/] end]
}

# extract module name from modulefile and currently enabled modulepaths
proc findModuleNameFromModulefile {modfile} {
   set ret {}

   foreach modpath [getModulePathList] {
      if {[string first $modpath/ $modfile/] == 0} {
         set ret [getModuleNameFromModulepath $modfile $modpath]
         break
      }
   }
   return $ret
}

# extract modulepath from modulefile and currently enabled modulepaths
proc findModulepathFromModulefile {modfile} {
   set ret {}

   foreach modpath [getModulePathList] {
      if {[string first $modpath/ $modfile/] == 0} {
         set ret $modpath
         break
      }
   }
   return $ret
}

# Determine with a name provided as argument the corresponding module name,
# version and name/version. Module name is guessed from current module name
# when shorthand version notation is used. Both name and version are guessed
# from current module if name provided is empty. If 'name_relative_tocur' is
# enabled then name argument may be interpreted as a name relative to the
# current modulefile directory (useful for module-version and module-alias
# for instance).
proc getModuleNameVersion {{name {}} {name_relative_tocur 0}} {
   set curmod [currentModuleName]
   set curmodname [file dirname $curmod]
   set curmodversion [file tail $curmod]

   if {$name eq {}} {
      set name $curmodname
      set version $curmodversion
   # check for shorthand version notation like "/version" or "./version"
   # only if we are currently interpreting a modulefile or modulerc
   } elseif {$curmod ne {} && [regexp {^\.?\/(.*)$} $name match version]} {
      # if we cannot distinguish a module name, raise error when shorthand
      # version notation is used
      if {$::ModulesCurrentModulefile ne $curmod && $curmod ne {.modulerc}} {
         # name is the name of current module directory
         set name $curmodname
      } else {
         reportError "Invalid modulename '$name' found"
         return {}
      }
   } else {
      set name [string trimright $name /]
      set version [file tail $name]
      if {$name eq $version} {
         set version {}
      } else {
         set name [file dirname $name]
      }
      # name may correspond to last part of current module
      # if so name is replaced by current module name
      if {$name_relative_tocur && [file tail $curmodname] eq $name} {
         set name $curmodname
      }
   }

   if {$version eq {}} {
      set mod $name
   } else {
      set mod $name/$version
   }

   return [list $mod $name $version]
}

# Register alias or symbolic version deep resolution in a global array that
# can be used thereafter to get in one query the actual modulefile behind
# a virtual name. Also consolidate a global array that in the same manner
# list all the symbols held by modulefiles.
proc setModuleResolution {mod target {symver {}} {override_res_path 1}} {
   global g_moduleResolved g_resolvedHash g_resolvedPath g_symbolHash

   # find end-point module and register step-by-step path to get to it
   set res $target
   set res_path $res
   while {$mod ne $res && [info exists g_resolvedPath($res)]} {
      set res $g_resolvedPath($res)
      lappend res_path $res
   }

   # error if resolution end on initial module
   if {$mod eq $res} {
      reportError "Resolution loop on '$res' detected"
      return 0
   }

   # module name will be useful when registering symbol
   if {$symver ne {}} {
      lassign [getModuleNameVersion $mod] modfull modname
   }

   # change default symbol owner if previously given
   if {$symver eq {default}} {
      # alternative name "modname" is set when mod = "modname/default" both
      # names will be registered to be known for queries and resolution defs
      set modalt $modname

      if {[info exists g_moduleResolved($mod)]} {
         set prev $g_moduleResolved($mod)
         # no test needed, there must be a "default" in $prev symbol list
         set idx [lsearch -exact $g_symbolHash($prev) default]
         reportDebug "remove symbol 'default' from '$prev'"
         set g_symbolHash($prev) [lreplace $g_symbolHash($prev) $idx $idx]
      }
   }

   # register end-point resolution
   reportDebug "$mod resolved to $res"
   set g_moduleResolved($mod) $res
   # set first element of resolution path only if not already set or
   # scratching enabled, no change when propagating symbol along res path
   if {$override_res_path || ![info exists g_resolvedPath($mod)]} {
      set g_resolvedPath($mod) $target
   }
   lappend g_resolvedHash($res) $mod

   # also register resolution on alternative name if any
   if {[info exists modalt]} {
      reportDebug "$modalt resolved to $res"
      set g_moduleResolved($modalt) $res
      if {$override_res_path || ![info exists g_resolvedPath($modalt)]} {
         set g_resolvedPath($modalt) $target
      }
      lappend g_resolvedHash($res) $modalt
      # register name alternative to know their existence
      set ::g_moduleAltName($modalt) $mod
      set ::g_moduleAltName($mod) $modalt
   }

   # if other modules were pointing to this one, adapt resolution end-point
   set relmod_list {}
   if {[info exists g_resolvedHash($mod)]} {
      set relmod_list $g_resolvedHash($mod)
      unset g_resolvedHash($mod)
   }
   # also adapt resolution for modules pointing to the alternative name
   if {[info exists modalt] && [info exists g_resolvedHash($modalt)]} {
      set relmod_list [concat $relmod_list $g_resolvedHash($modalt)]
      unset g_resolvedHash($modalt)
   }
   foreach relmod $relmod_list {
      set g_moduleResolved($relmod) $res
      reportDebug "$relmod now resolved to $res"
      lappend g_resolvedHash($res) $relmod
   }

   # register and propagate symbols to the resolution path
   set sym_list [expr {[info exists g_symbolHash($mod)] ? $g_symbolHash($mod)\
      : {}}]
   if {$symver ne {}} {
      # merge symbol definitions in case of alternative name
      if {[info exists modalt] && [info exists g_symbolHash($modalt)]} {
         set sym_list [lsort -dictionary -unique [concat $sym_list\
            $g_symbolHash($modalt)]]
         reportDebug "set symbols '$sym_list' to $mod and $modalt"
         set g_symbolHash($mod) $sym_list
         set g_symbolHash($modalt) $sym_list
      }

      # dictionary-sort symbols and remove eventual duplicates
      set sym_list [lsort -dictionary -unique [concat $sym_list\
         [list $symver]]]

      # propagate symbols in g_symbolHash and g_moduleVersion toward the
      # resolution path, handle that locally if we still work on same
      # modulename, call for a proper resolution as soon as we change of
      # module to get this new resolution registered
      foreach modres $res_path {
         lassign [getModuleNameVersion $modres] modfull modresname
         if {$modname eq $modresname} {
            if {[info exists g_symbolHash($modres)]} {
               set modres_sym_list [lsort -dictionary -unique [concat\
                  $g_symbolHash($modres) $sym_list]]
            } else {
               set modres_sym_list $sym_list
            }
            # sync symbols of alternative name if any
            if {[info exists ::g_moduleAltName($modres)]} {
               set altmodres $::g_moduleAltName($modres)
               reportDebug "set symbols '$modres_sym_list' to $modres and\
                  $altmodres"
               set g_symbolHash($altmodres) $modres_sym_list
            } else {
               reportDebug "set symbols '$modres_sym_list' to $modres"
            }
            set g_symbolHash($modres) $modres_sym_list

            # register symbolic version for querying in g_moduleVersion
            foreach symelt $sym_list {
               set modvers $modresname/$symelt
               reportDebug "module-version $modvers = $modres"
               set ::g_moduleVersion($modvers) $modres
               set ::g_sourceVersion($modvers) $::ModulesCurrentModulefile
            }
         # as we change of module name a proper resolution call should be
         # made (see below) and will handle the rest of the resolution path
         } else {
            set need_set_res 1
            break
         }
      }
   # when registering an alias, existing symbols on alias source name should
   # be broadcast along the resolution path with a proper resolution call
   # (see below)
   } else {
      lassign [getModuleNameVersion $target] modres modresname
      set need_set_res 1
   }

   # resolution needed to broadcast symbols along resolution path without
   # altering initial path already set for these symbols
   if {[info exists need_set_res]} {
      foreach symelt $sym_list {
         set modvers $modresname/$symelt
         reportDebug "set resolution for $modvers"
         setModuleResolution $modvers $modres $symelt 0
      }
   }

   return 1
}

# retrieve all names that resolve to passed mod
proc getAllModuleResolvedName {mod} {
   set namelist {}

   # get parent directories of mod
   foreach modelt [split $mod /] {
      if {[info exists modroot]} {
         append modroot /
      }
      append modroot $modelt
      lappend resmodlist $modroot
   }

   # add additionnaly all the altnames set on directories, parents of mod
   # or on distant directories whose default version resolves to mod
   for {set i 0} {$i < [llength $resmodlist]} {incr i 1} {
      set modelt [lindex $resmodlist $i]
      if {[info exists ::g_resolvedHash($modelt)]} {
         foreach resmod $::g_resolvedHash($modelt) {
            # if modelt is not a parent directory of mod, check its resolution
            # points to mod (directly for alias/sym or indirectly for dir
            # whose default version bridge resolution toward mod)
            if {[string first $modelt/ $mod/] == 0 ||\
               $::g_moduleResolved($resmod) eq $mod || [lindex\
               [getPathToModule $::g_moduleResolved($resmod)] 1] eq $mod} {
               appendNoDupToList namelist $resmod

               unset modroot
               foreach reselt [split [file dirname $resmod] /] {
                  if {[info exists modroot]} {
                     append modroot /
                  }
                  append modroot $reselt
                  appendNoDupToList resmodlist $modroot
               }
            }
         }
      }
   }
   return $namelist
}

# Specifies a default or alias version for a module that points to an 
# existing module version Note that aliases defaults are stored by the
# short module name (not the full path) so aliases and defaults from one
# directory will apply to modules of the same name found in other
# directories.
proc module-version {args} {
   reportDebug $args
   lassign [getModuleNameVersion [lindex $args 0] 1] mod modname modversion

   # go for registration only if valid modulename
   if {$mod ne {}} {
      foreach version [lrange $args 1 end] {
         set aliasversion $modname/$version
         # do not alter a previously defined alias version
         if {![info exists ::g_moduleVersion($aliasversion)]} {
            setModuleResolution $aliasversion $mod $version
         } else {
            reportWarning "Symbolic version '$aliasversion' already defined"
         }
      }
   }

   return {}
}

proc module-alias {args} {
   lassign [getModuleNameVersion [lindex $args 0]] alias
   lassign [getModuleNameVersion [lindex $args 1] 1] mod

   reportDebug "$alias = $mod"

   if {[setModuleResolution $alias $mod]} {
      set ::g_moduleAlias($alias) $mod
      set ::g_sourceAlias($alias) $::ModulesCurrentModulefile
   }

   return {}
}

proc module-virtual {args} {
   lassign [getModuleNameVersion [lindex $args 0]] mod
   set modfile [getAbsolutePath [lindex $args 1]]

   reportDebug "$mod = $modfile"

   set ::g_moduleVirtual($mod) $modfile
   set ::g_sourceVirtual($mod) $::ModulesCurrentModulefile

   return {}
}

proc module {command args} {
   set mode [currentMode]

   # resolve command if alias or shortcut name used
   switch -regexp -- $command {
      {^(add|lo)}              {set command "load"}
      {^(rm|del|unlo|remove$)} {set command "unload"}
      {^(ref|rel)}             {set command "reload"}
      {^sw}                    {set command "switch"}
      {^(di|show)}             {set command "display"}
      {^av}                    {set command "avail"}
      {^al}                    {set command "aliases"}
      {^li}                    {set command "list"}
      {^wh}                    {set command "whatis"}
      {^(apropos|keyword)$}    {set command "search"}
      {^pu}                    {set command "purge"}
      {^init(a|lo)}            {set command "initadd"}
      {^initp}                 {set command "initprepend"}
      {^initsw}                {set command "initswitch"}
      {^init(rm|unlo)$}        {set command "initrm"}
      {^initl}                 {set command "initlist"}
      {^$} {
         # default command is help if empty string supplied
         set command help
         # clear other args if no command name supplied
         set args {}
      }
   }

   reportDebug "cmd='$command', args='$args'"

   # parse options, do that globally to ignore options not related to a given
   # module sub-command (exclude them from arg list)
   lassign [eval parseModuleCommandArgs $command $args] show_oneperline\
      show_mtime show_filter search_filter dump_state args

   # guess if called from top level
   set topcall [expr {[getEvalModuleStackDepth] == 0}]
   if {$topcall} {
      set msgprefix {}
   } else {
      set msgprefix {module: }

      # some commands can only be called from top level, not within modulefile
      switch -- $command {
         path - paths - autoinit - help - prepend-path - append-path -\
         remove-path - is-loaded - is-saved - is-used - is-avail -\
         info-loaded - clear - config {
            set errormsg "${msgprefix}Command '$command' not supported"
         }
      }
   }

   # argument number check
   switch -- $command {
      unload - source - display - initadd - initprepend - initrm - test -\
      is-avail {
         if {[llength $args] == 0} {
            set argnberr 1
         }
      }
      reload - aliases - list - purge - savelist - initlist - initclear -\
      autoinit {
         if {[llength $args] != 0} {
            set argnberr 1
         }
      }
      switch {
         if {[llength $args] == 0 || [llength $args] > 2} {
            set argnberr 1
         }
      }
      path - paths - info-loaded {
         if {[llength $args] != 1} {
            set argnberr 1
         }
      }
      search - save - restore - saverm - saveshow - clear {
         if {[llength $args] > 1} {
            set argnberr 1
         }
      }
      initswitch {
         if {[llength $args] != 2} {
            set argnberr 1
         }
      }
      prepend-path - append-path - remove-path {
         if {[llength $args] < 2} {
            set argnberr 1
         }
      }
      config {
         if {[llength $args] > 2} {
            set argnberr 1
         }
      }
   }
   if {[info exists argnberr]} {
      set errormsg "Unexpected number of args for '$command' command"
   }

   # skip command processing if error already spotted
   if {![info exists errormsg]} {
      # define if modfile should always be fully read even for validity check
      pushAlwaysReadFullFile [expr {[isInList [list path paths list avail\
         aliases] $command]} ? 0 : 1]
      pushCommandName $command

      if {$topcall} {
         # Find and execute any global rc file found
         runModulerc
      }

      switch -- $command {
         load {
            # ignore flag used in collection to track non-user asked state
            set args [replaceFromList $args --notuasked]
            # no error raised on empty argument list to cope with
            # initadd command that may expect this behavior
            if {[llength $args] > 0} {
               set ret 0
               # if top command is source, consider module load commands made
               # within sourced file evaluation as top load command
               if {$topcall || ([getEvalModuleStackDepth] == 1 && (
                  [aboveCommandName] eq {source} || [aboveCommandName] eq\
                  {autoinit}))} {
                  set ret [eval cmdModuleLoad load 1 $args]
               } elseif {$mode eq {load}} {
                  # load here if no auto mode, done through prereq elsewhere
                  # inhibited if currently in DepRe context
                  if {![getAutoHandling] && [currentModuleEvalContext] ne\
                     {depre} && ![eval is-loaded $args] && ![eval is-loading\
                     $args]} {
                     set ret [eval cmdModuleLoad reqlo 0 $args]
                     # ignore obtained error if force mode enabled
                     if {[getForce]} {
                        set ret 0
                     }
                  }
                  # register modulefiles to load as individual prereqs
                  foreach arg $args {
                     prereq $arg
                  }
               # mods unload is handled via UReqUn mechanism when auto enabled
               } elseif {![getAutoHandling]} {
                  # on unload mode, unload mods in reverse order, if loaded
                  # prior this mod, if not user asked and not required by
                  # other loaded mods
                  set modlist [getLoadedModuleList]
                  set modidx [lsearch -exact $modlist [currentModuleName]]
                  if {$modidx != 0} {
                     set priormodlist [lrange $modlist 0 $modidx]
                     foreach arg [lreverse $args] {
                        if {[set unmod [getLoadedMatchingName $arg returnlast\
                           0 $priormodlist]] ne {}} {
                           if {[cmdModuleUnload urequn match 1 0 1 1\
                              $unmod]} {
                              reportWarning "Unload of useless requirement\
                                 $unmod failed" 1
                           }
                        }
                     }
                  }
               }
               # sub-module interpretation failed, raise error
               if {$ret && !$topcall} {
                  set errormsg SUB_FAILED
               }
            }
         }
         unload {
            # if top command is source, consider module load commands made
            # within sourced file evaluation as top load command
            if {$topcall || ([getEvalModuleStackDepth] == 1 && (
               [aboveCommandName] eq {source} || [aboveCommandName] eq\
               {autoinit}))} {
               set ret [eval cmdModuleUnload unload match 1 0 0 0 $args]
            } elseif {$mode eq {load}} {
               # unload mods only on load mode, nothing done on unload mode as
               # the registered conflict guarantees the target module cannot
               # be loaded unless forced
               # do not unload module required by others even in force mode
               set ret [eval cmdModuleUnload conun match 0 0 0 1 $args]

               # register modulefiles to unload as individual conflicts
               foreach arg $args {
                  # do not break on error yet, go through the whole modfile
                  # evaluation in case conflict is solved later on
                  catch {conflict $arg}
               }
               # sub-module interpretation failed, raise error
               if {$ret} {
                  set errormsg SUB_FAILED
               }
            }
         }
         reload {
            cmdModuleReload
         }
         use {
            if {$topcall || $mode eq {load}} {
               eval cmdModuleUse $args
            } else {
               eval cmdModuleUnuse $args
            }
         }
         unuse {
            eval cmdModuleUnuse $args
         }
         source {
            if {$topcall || $mode eq {load}} {
               eval cmdModuleSource $args
            } else {
               # on unload mode, unsource script in reverse order
               eval cmdModuleUnsource [lreverse $args]
            }
         }
         switch {
            # pass 'user asked state' to switch procedure
            set uasked [expr {$topcall || ([getEvalModuleStackDepth] == 1 &&\
               ([aboveCommandName] eq {source} || [aboveCommandName] eq\
               {autoinit}))}]
            if {$uasked} {
               eval cmdModuleSwitch $uasked $args
            } else {
               # CAUTION: it is not recommended to use the `switch`
               # sub-command in modulefiles as this command is intended for
               # the command-line for a 2in1 operation. Could be removed from
               # the modulefile scope in a future release. Use `module unload`
               # and `module load` commands in modulefiles instead.

               switch -- $mode {
                  load {
                     eval cmdModuleSwitch $uasked $args
                  }
                  unload {
                     # find what has been asked for unload and load
                     lassign $args swunmod swlomod
                     if {$swlomod eq {} && $swunmod ne {}} {
                        set swlomod $swunmod
                     }

                     # apply same mechanisms than for 'module load' and
                     # 'module unload' for an unload evaluation: nothing done
                     # for switched-off module and unload of switched-on
                     # module. If auto handling is enabled switched-on module
                     # is handled via UReqUn mechanism
                     if {![getAutoHandling] && $swlomod ne {}} {
                        # unload mod if it was loaded prior this mod, not user
                        # asked and not required by another loaded module
                        set modlist [getLoadedModuleList]
                        set modidx [lsearch -exact $modlist [currentModuleName]]
                        if {$modidx != 0} {
                           set priormodlist [lrange $modlist 0 $modidx]
                           if {[set unmod [getLoadedMatchingName $swlomod\
                              returnlast 0 $priormodlist]] ne {}} {
                              if {[cmdModuleUnload urequn match 1 0 1 1\
                                 $unmod]} {
                                 reportWarning "Unload of useless requirement\
                                    $unmod failed" 1
                              }
                           }
                        }
                     }
                  }
               }
            }
         }
         display {
            eval cmdModuleDisplay $args
         }
         avail {
            eval cmdModuleAvail $show_oneperline $show_mtime "{$show_filter}"\
               "{$search_filter}" $args
         }
         aliases {
            cmdModuleAliases
         }
         path {
            eval cmdModulePath $args
         }
         paths {
            eval cmdModulePaths $args
         }
         list {
            cmdModuleList $show_oneperline $show_mtime
         }
         whatis {
            if {$args ne {}} {
               foreach arg $args {
                  cmdModuleWhatIs $arg
               }
            } else {
               cmdModuleWhatIs
            }
         }
         search {
            eval cmdModuleApropos $args
         }
         purge {
            eval cmdModulePurge
         }
         save {
            eval cmdModuleSave $args
         }
         restore {
            eval cmdModuleRestore $args
         }
         saverm {
            eval cmdModuleSaverm $args
         }
         saveshow {
            eval cmdModuleSaveshow $args
         }
         savelist {
            cmdModuleSavelist $show_oneperline $show_mtime
         }
         initadd {
            eval cmdModuleInit add $args
         }
         initprepend {
            eval cmdModuleInit prepend $args
         }
         initswitch {
            eval cmdModuleInit switch $args
         }
         initrm {
            eval cmdModuleInit rm $args
         }
         initlist {
            eval cmdModuleInit list $args
         }
         initclear {
            eval cmdModuleInit clear $args
         }
         autoinit {
            cmdModuleAutoinit
         }
         clear {
            # ensure empty string is correctly passed
            eval cmdModuleClear "{$args}"
         }
         config {
            eval cmdModuleConfig $dump_state $args
         }
         help {
            eval cmdModuleHelp $args
         }
         test {
            eval cmdModuleTest $args
         }
         prepend-path - append-path - remove-path - is-loaded - is-saved -\
         is-used - is-avail {
            eval cmdModuleResurface $command $args
         }
         info-loaded {
            eval cmdModuleResurface module-info loaded $args
         }
         default {
            set errormsg "${msgprefix}Invalid command '$command'"
         }
      }
      popCommandName
      popAlwaysReadFullFile
   }

   # if an error need to be raised, proceed differently depending of
   # call level: if called from top level render errors then raise error
   # elsewhere call is made from a modulefile or modulerc and error
   # will be managed from execute-modulefile or execute-modulerc
   if {[info exists errormsg]} {
      if {$topcall} {
         reportErrorAndExit "$errormsg\nTry 'module --help'\
            for more information."
      } else {
         error $errormsg
      }
   # if called from top level render settings if any
   } elseif {$topcall} {
      renderSettings
   }

   return {}
}

proc getModshareVarName {var} {
   # specific modshare variable for DYLD-related variables as a suffixed
   # variable will lead to warning messages with this tool
   if {[string range $var 0 4] eq {DYLD_}} {
      return MODULES_MODSHARE_${var}
   } else {
      return ${var}_modshare
   }
}

proc setenv {var val} {
   reportDebug "var='$var', val='$val'"

   # clean any previously defined reference counter array
   unset-env [getModshareVarName $var] 1

   # Set the variable for later use during the modulefile evaluation
   set-env $var $val

   return {}
}

# undo setenv in unload mode
proc setenv-un {var val} {
   reportDebug "var='$var', val='$val'"

   # clean any existing reference counter array
   unset-env [getModshareVarName $var] 1

   # Add variable to the list of variable to unset in shell output code but
   # set it in interp context as done on load mode for later use during the
   # modulefile evaluation
   unset-env $var 0 $val

   return {}
}

# optimized setenv/unsetenv for whatis mode: init env variable with an empty
# value if undefined. do not care about value, just avoid variable to be
# undefined for later use during the modulefile evaluation
proc setenv-wh {var args} {
   if {![info exists ::env($var)]} {
      reportDebug "var='$var', val=''"
      set ::env($var) {}
   }
   return {}
}

proc getenv {var {valifundef _UNDEFINED_}} {
   reportDebug "var='$var', valifundef='$valifundef'"

   return [expr {[currentMode] ne {display} ? [get-env $var $valifundef] :\
      "\$$var"}]
}

proc unsetenv {var {val {}}} {
   reportDebug "var='$var', val='$val'"

   # clean any existing reference counter array
   unset-env [getModshareVarName $var] 1

   # Set the variable for later use during the modulefile evaluation
   unset-env $var

   return {}
}

# undo unsetenv in unload mode
proc unsetenv-un {var {val {}}} {
   if {$val ne {}} {
      return [setenv $var $val]
   } else {
      return [unsetenv $var]
   }
}

proc chdir {dir} {
   reportDebug $dir

   if {[file exists $dir] && [file isdirectory $dir]} {
      set ::g_changeDir $dir
   } else {
      # report issue but does not treat it as an error to have the
      # same behavior as C-version
      reportWarning "Cannot chdir to '$dir' for '[currentModuleName]'"
   }

   return {}
}

# superseed exit command to handle it if called within a modulefile
# rather than exiting the whole process
proc exitModfileCmd {{code 0}} {
   set mode [currentMode]

   reportDebug ($code)

   if {$mode eq {load}} {
      reportDebug {Inhibit next modulefile interpretations}
      set ::g_inhibit_interp 1
   }

   # break to gently end interpretation of current modulefile
   return -code break
}

# enables slave interp to return ModulesVersion value to the master interp
proc setModulesVersion {val} {
   set ::ModulesVersion $val
}

# supersede puts command to catch content sent to stdout/stderr within
# modulefile in order to correctly send stderr content (if a pager has been
# enabled) or postpone content channel send after rendering on stdout the
# relative environment changes required by the modulefile
proc putsModfileCmd {itrp args} {
   reportDebug "$args (itrp=$itrp)"

   # determine if puts call targets the stdout or stderr channel
   switch -- [llength $args] {
      1 {
         set deferPuts 1
      }
      2 {
         switch -- [lindex $args 0] {
            -nonewline - stdout {
               set deferPuts 1
            }
            stderr {
               set reportArgs [list [lindex $args 1]]
            }
         }
      }
      3 {
         if {[lindex $args 0] eq {-nonewline}} {
            switch -- [lindex $args 1] {
               stdout {
                  set deferPuts 1
               }
               stderr {
                  set reportArgs [list [lindex $args 2] 1]
               }
            }
         } else {
            set wrongNumArgs 1
         }
      }
      default {
         set wrongNumArgs 1
      }
   }

   # raise error if bad argument number detected, do this here rather in _puts
   # not to confuse people with an error reported by an internal name (_puts)
   if {[info exists wrongNumArgs]} {
      error {wrong # args: should be "puts ?-nonewline? ?channelId? string"}
   # defer puts if it targets stdout (see renderSettings)
   } elseif {[info exists deferPuts]} {
      lappend ::g_stdoutPuts $args
   # if it targets stderr call report, which knows what channel to use
   } elseif {[info exists reportArgs]} {
      eval report $reportArgs
   # pass to real puts command if not related to stdout and do that in modfile
   # interpreter context to get access to eventual specific channel
   } else {
      $itrp eval _puts $args
   }
}

########################################################################
# path fiddling
#
proc getReferenceCountArray {var separator} {
   # get reference counter set in environment
   set sharevar [getModshareVarName $var]
   array set refcount {}
   if {[info exists ::env($sharevar)]} {
      set modsharelist [psplit $::env($sharevar) [getPathSeparator]]
      # ignore environment ref count variable if malformed
      if {([llength $modsharelist] % 2) == 0} {
         array set refcount $modsharelist
      } else {
         reportDebug "Reference counter value in '$sharevar' is malformed\
            ($modsharelist)"
      }
   }

   array set countarr {}
   if {[info exists ::env($var)]} {
      # do not skip a bare empty path entry that can also be found in
      # reference counter array (sometimes var is cleared by setting it
      # empty not unsetting it, ignore var in this case)
      if {$::env($var) eq {} && [info exists refcount()]} {
         lappend eltlist {}
      } else {
         set eltlist [split $::env($var) $separator]
      }

      # just go thought the elements of the variable, which means additional
      # elements part of the reference counter variable will be ignored
      foreach elt $eltlist {
         # no reference counter, means value has been set once
         if {![info exists refcount($elt)]} {
            set count 1
         # bad reference counter value is ignored
         } elseif {![string is digit -strict $refcount($elt)]} {
            reportDebug "Reference counter value for '$elt' in '$sharevar' is\
               erroneous ($refcount($elt))"
            set count 1
         } else {
            set count $refcount($elt)
         }
         set countarr($elt) $count
      }
   }

   set count_list [array get countarr]
   reportDebug "(var=$var, delim=$separator) got '$count_list'"

   return $count_list
}


proc unload-path {args} {
   reportDebug ($args)

   lassign [eval parsePathCommandArgs unload-path $args] separator\
      allow_dup idx_val var path_list

   array set countarr [getReferenceCountArray $var $separator]

   # Don't worry about dealing with this variable if it is already scheduled
   #  for deletion
   if {[info exists ::g_stateEnvVars($var)] && $::g_stateEnvVars($var) eq\
      {del}} {
      return {}
   }

   # save initial variable content to match index arguments
   set dir_list [split [get-env $var] $separator]
   # detect if empty env value means empty path entry
   if {[llength $dir_list] == 0 && [info exists countarr()]} {
      lappend dir_list {}
   }

   # build list of index to remove from variable
   set del_idx_list [list]
   foreach dir $path_list {
      # retrieve dir value if working on an index list
      if {$idx_val} {
         set idx $dir
         # go to next index if this one is not part of the existing range
         # needed to distinguish an empty value to an out-of-bound value
         if {$idx < 0 || $idx >= [llength $dir_list]} {
            continue
         } else {
            set dir [lindex $dir_list $idx]
         }
      }

      # update reference counter array
      if {[info exists countarr($dir)]} {
         incr countarr($dir) -1
         set newcount $countarr($dir)
         if {$countarr($dir) <= 0} {
            unset countarr($dir)
         }
      } else {
         set newcount 0
      }

      # get all entry indexes corresponding to dir
      set found_idx_list [lsearch -all -exact $dir_list $dir]

      # remove all found entries
      if {$newcount <= 0} {
         # only remove passed position in --index mode
         if {$idx_val} {
            lappend del_idx_list $idx
         } else {
            set del_idx_list [concat $del_idx_list $found_idx_list]
         }
      # if multiple entries found remove the extra entries compared to new
      # reference counter
      } elseif {[llength $found_idx_list] > $newcount} {
         # only remove passed position in --index mode
         if {$idx_val} {
            lappend del_idx_list $idx
         } else {
            # delete extra entries, starting from end of the list (on a path
            # variable, entries at the end have less priority than those at
            # the start)
            set del_idx_list [concat $del_idx_list [lrange $found_idx_list\
               $newcount end]]
         }
      }
   }

   # update variable if some element need to be removed
   if {[llength $del_idx_list] > 0} {
      set del_idx_list [lsort -integer -unique $del_idx_list]
      set newpath [list]
      set nbelem [llength $dir_list]
      # rebuild list of element without indexes set for deletion
      for {set i 0} {$i < $nbelem} {incr i} {
         if {[notInList $del_idx_list $i]} {
            lappend newpath [lindex $dir_list $i]
         }
      }
   } else {
      set newpath $dir_list
   }

   # set env variable and corresponding reference counter in any case
   if {[llength $newpath] == 0} {
      unset-env $var
   } else {
      set-env $var [join $newpath $separator]
   }

   set sharevar [getModshareVarName $var]
   if {[array size countarr] > 0} {
      set-env $sharevar [pjoin [array get countarr] [getPathSeparator]]
   } else {
      unset-env $sharevar 1
   }
   return {}
}

proc add-path {pos args} {
   reportDebug "($args) pos=$pos"

   lassign [eval parsePathCommandArgs add-path $args] separator allow_dup\
      idx_val var path_list

   set sharevar [getModshareVarName $var]
   array set countarr [getReferenceCountArray $var $separator]

   if {$pos eq {prepend}} {
      set path_list [lreverse $path_list]
   }

   set val [get-env $var]

   foreach dir $path_list {
      if {![info exists countarr($dir)] || $allow_dup} {
         # ignore env var set empty if no empty entry found in reference
         # counter array (sometimes var is cleared by setting it empty not
         # unsetting it)
         if {$val ne {} || [info exists countarr()]} {
            set val [expr {$pos eq {prepend} ? "$dir$separator$val" :\
               "$val$separator$dir"}]
         } else {
            set val $dir
         }
      }
      if {[info exists countarr($dir)]} {
         incr countarr($dir)
      } else {
         set countarr($dir) 1
      }
   }

   set-env $var $val
   set-env $sharevar [pjoin [array get countarr] [getPathSeparator]]

   return {}
}

# analyze argument list passed to a path command to set default value or raise
# error in case some attributes are missing
proc parsePathCommandArgs {cmd args} {
   # parse argument list
   set next_is_delim 0
   set allow_dup 0
   set idx_val 0
   foreach arg $args {
      switch -glob -- $arg {
         --index {
            if {$cmd eq {add-path}} {
               reportWarning "--index option has no effect on $cmd"
            } else {
               set idx_val 1
            }
         }
         --duplicates {
            if {$cmd eq {unload-path}} {
               reportWarning "--duplicates option has no effect on $cmd"
            } else {
               set allow_dup 1
            }
         }
         -d - -delim - --delim {
            set next_is_delim 1
         }
         --delim=* {
            set delim [string range $arg 8 end]
         }
         -* {
            error "invalid option '$arg' for $cmd"
         }
         default {
            if {$next_is_delim} {
               set delim $arg
               set next_is_delim 0
            } elseif {![info exists var]} {
               set var $arg
            } else {
               # set multiple passed values in a list
               lappend val_raw_list $arg
            }
         }
      }
   }

   # adapt with default value or raise error if some arguments are missing
   if {![info exists delim]} {
      set delim [getPathSeparator]
   } elseif {$delim eq {}} {
      error "$cmd should get a non-empty path delimiter"
   }
   if {![info exists var]} {
      error "$cmd should get an environment variable name"
   } elseif {$var eq {}} {
      error "$cmd should get a valid environment variable name"
   }
   if {![info exists val_raw_list]} {
      error "$cmd should get a value for environment variable $var"
   }

   # set list of value to add
   set val_list [list]
   foreach val $val_raw_list {
      # check passed indexes are numbers
      if {$idx_val && ![string is integer -strict $val]} {
         error "$cmd should get valid number as index value"
      }

      switch -- $val \
         {} {
            # add empty entry in list
            lappend val_list {}
         } \
         $delim {
            error "$cmd cannot handle path equals to separator string"
         } \
         default {
            # split passed value with delimiter
            set val_list [concat $val_list [split $val $delim]]
         }
   }

   reportDebug "(delim=$delim, allow_dup=$allow_dup, idx_val=$idx_val,\
      var=$var, val=$val_list, nbval=[llength $val_list])"

   return [list $delim $allow_dup $idx_val $var $val_list]
}

proc prepend-path {args} {
   reportDebug $args

   # Set the variable for later use during the modulefile evaluation
   eval add-path prepend $args

   return {}
}

proc append-path {args} {
   reportDebug $args

   # Set the variable for later use during the modulefile evaluation
   eval add-path append $args

   return {}
}

proc remove-path {args} {
   reportDebug $args

   # Set the variable for later use during the modulefile evaluation
   eval unload-path $args

   return {}
}

# undo remove-path in unload mode
proc remove-path-un {args} {
   # clear variable if it does not exist on unload mode for later use
   # during the modulefile evaluation
   lassign [eval parsePathCommandArgs unload-path $args] separator\
      allow_dup idx_val var path_list
   if {![info exists ::env($var)]} {
      reset-to-unset-env $var
   }
}

# optimized *-path for whatis mode: init env variable with an empty value if
# undefined. do not care about value, just avoid variable to be undefined for
# later use during the modulefile evaluation
proc edit-path-wh {args} {
   reportDebug $args

   # get variable name
   lassign [eval parsePathCommandArgs edit-path-wh $args] separator\
      allow_dup idx_val var path_list

   if {![info exists ::env($var)]} {
      set ::env($var) {}
   }

   return {}
}

proc set-alias {alias what} {
   reportDebug "alias='$alias', val='$what'"

   set ::g_Aliases($alias) $what
   set ::g_stateAliases($alias) new

   return {}
}

# undo set-alias in unload mode
proc set-alias-un {alias what} {
   return [unset-alias $alias]
}

proc unset-alias {alias} {
   reportDebug alias='$alias'

   set ::g_Aliases($alias) {}
   set ::g_stateAliases($alias) del

   return {}
}

proc set-function {function what} {
   reportDebug "function='$function', val='$what'"

   set ::g_Functions($function) $what
   set ::g_stateFunctions($function) new

   return {}
}

# undo set-function in unload mode
proc set-function-un {function what} {
   return [unset-function $function]
}

proc unset-function {function} {
   reportDebug function='$function'

   set ::g_Functions($function) {}
   set ::g_stateFunctions($function) del

   return {}
}


proc is-loaded {args} {
   reportDebug $args

   foreach mod $args {
      if {[getLoadedMatchingName $mod returnfirst] ne {}} {
         return 1
      }
   }
   # is something loaded whatever it is?
   return [expr {[llength $args] == 0 && [llength [getLoadedModuleList]] > 0}]
}

proc is-loading {args} {
   reportDebug $args

   foreach mod $args {
      if {[getLoadedMatchingName $mod returnfirst 1] ne {}} {
         return 1
      }
   }
   # is something else loading whatever it is?
   return [expr {[llength $args] == 0 && [llength [getLoadingModuleList]] >1}]
}

proc conflict {args} {
   reportDebug $args
   set currentModule [currentModuleName]

   # register conflict list
   eval setLoadedConflict $currentModule $args

   foreach mod $args {
      # if the conflict module is loading and it does not correspond to
      # currently evaluated module, we cannot proceed
      set isloading [expr {![doesModuleMatchesName $currentModule $mod] &&\
         [is-loading $mod]}]
      # if the conflicting module is loaded, we cannot either
      if {[is-loaded $mod] || $isloading} {
         set retisconun [eval isModuleEvaluated conun $mod]
         # report message on currently evaluated module message block
         if {![set retiseval [eval isModuleEvaluated any $mod]] ||\
            [currentMsgRecordId] ne [topMsgRecordId] || !$retisconun} {
            # more appropriate msg if an eval was attempted or is by-passed
            set msg [expr {$retiseval || [getForce] ? [getConIsLoadedMsg\
               $mod $isloading] : [getErrConflictMsg $currentModule $mod]}]

            # still proceed if force mode enabled
            if {[getForce]} {
               reportWarning $msg
               # indicate message has already been reported
               lappend ::report_conflict($currentModule) $mod
            } else {
               error "GLOBALERR $msg"
            }
         }
      }
   }

   return {}
}

proc prereq {args} {
   reportDebug $args
   set currentModule [currentModuleName]

   # register prereq list (sets of optional prereq are registered as list)
   setLoadedPrereq $currentModule $args

   # if dependency resolving is enabled try to load prereq
   if {[getAutoHandling] && ![eval is-loaded $args] && ![eval is-loading\
      $args]} {
      set imax [llength $args]
      set prereqloaded 0
      # if prereq list specified, try to load first then
      # try next if load of first module not successful
      for {set i 0} {$i<$imax && $prereqloaded==0} {incr i 1} {
         set arg [lindex $args $i]

         # hold output of each evaluation until they are all done to drop
         # those that failed if one succeed
         set curholdid load-$i-$arg
         pushReportHoldId $curholdid
         if {[catch {cmdModuleLoad reqlo 0 $arg} errorMsg]} {
            # if an error is raised, release output and rethrow the error
            # (could be raised if no modulepath defined for instance)
            popReportHoldId
            lappend holdidlist $curholdid report
            eval releaseHeldReport $holdidlist
            error $errorMsg
         }
         popReportHoldId

         if {[is-loaded $arg]} {
            set prereqloaded 1
            # set previous reports to be dropped as this one succeed
            if {[info exists holdidlist]} {
               foreach {holdid action} $holdidlist {
                  lappend newholdidlist $holdid drop
               }
               set holdidlist $newholdidlist
            }
         }
         lappend holdidlist $curholdid report
      }
      # output held messages
      eval releaseHeldReport $holdidlist
   }

   if {![eval is-loaded $args] && ![eval is-loading $args]} {
      set retisreqlo [eval isModuleEvaluated reqlo $args]
      # report message on currently evaluated module message block
      if {![set retiseval [eval isModuleEvaluated any $args]] ||\
         [currentMsgRecordId] ne [topMsgRecordId] || !$retisreqlo} {

         # more appropriate msg if an evaluation was attempted or is by-passed
         set msg [expr {$retiseval || [getForce] ? [getReqNotLoadedMsg $args]\
            : [getErrPrereqMsg $currentModule $args]}]
         # still proceed if force mode enabled
         if {[getForce]} {
            reportWarning $msg
         # no error raise if done later
         } elseif {$retisreqlo} {
            reportError $msg
         } else {
            error "GLOBALERR $msg"
         }
      }

      # raise reqlo-specific msg to top level if attempted
      if {$retisreqlo} {
         set msg [getErrReqLoMsg $args]
         if {[getForce]} {
            reportWarning $msg 1
         } else {
            error "GLOBALERRTOP $msg"
         }
      }
   }

   return {}
}

proc x-resource {resource {value {}}} {
   reportDebug "($resource, $value)"

   # sometimes x-resource value may be provided within resource name
   # as the "x-resource {Ileaf.popup.saveUnder: True}" example provided
   # in manpage. so here is an attempt to extract real resource name and
   # value from resource argument
   if {[string length $value] == 0 && ![file exists $resource]} {
      # look first for a space character as delimiter, then for a colon
      set sepapos [string first { } $resource]
      if { $sepapos == -1 } {
         set sepapos [string first : $resource]
      }

      if { $sepapos > -1 } {
         set value [string range $resource [expr {$sepapos + 1}] end]
         set resource [string range $resource 0 [expr {$sepapos - 1}]]
         reportDebug "corrected ($resource, $value)"
      } else {
         # if not a file and no value provided x-resource cannot be
         # recorded as it will produce an error when passed to xrdb
         reportWarning "x-resource $resource is not a valid string or file"
         return {}
      }
   }

   # check current environment can handle X11 resource edition elsewhere exit
   if {[catch {runCommand xrdb -query} errMsg]} {
      if {[string range $errMsg 0 9] eq {GLOBALERR }} {
         set errMsg [string range $errMsg 10 end]
      }
      error "GLOBALERR X11 resources cannot be edited, issue spotted\n[sgr er\
         ERROR]: $errMsg"
   }

   # if a resource does hold an empty value in g_newXResources or
   # g_delXResources arrays, it means this is a resource file to parse
   if {[currentMode] eq {load}} {
      set ::g_newXResources($resource) $value
   } else {
      set ::g_delXResources($resource) $value
   }

   return {}
}

proc uname {what} {
   set result {}

   reportDebug $what

   if {! [info exists ::unameCache($what)]} {
      switch -- $what {
         sysname {
            set result $::tcl_platform(os)
         }
         machine {
            set result $::tcl_platform(machine)
         }
         nodename - node {
            set result [runCommand uname -n]
         }
         release {
            set result $::tcl_platform(osVersion)
         }
         domain {
            set result [runCommand domainname]
         }
         version {
            set result [runCommand uname -v]
         }
         default {
            error "uname $what not supported"
         }
      }
      set ::unameCache($what) $result
   }

   return $::unameCache($what)
}

# run shell command
proc system {args} {
   reportDebug $args

   set mode [currentMode]
   set status {}

   switch -- $mode {
      load - unload {
         # run through the appropriate shell
         if {[isWin]} {
            set shell cmd.exe
            set shellarg /c
         } else {
            set shell /bin/sh
            set shellarg -c
         }

         if {[catch {exec >&@stderr $shell $shellarg [join $args]}]} {
             # non-zero exit status, get it:
             set status [lindex $::errorCode 2]
         } else {
             # exit status was 0
             set status 0
         }
      }
   }

   return $status
}

# test at least one of the collections passed as argument exists
proc is-saved {args} {
   reportDebug $args

   foreach coll $args {
      lassign [getCollectionFilename $coll] collfile colldesc
      if {[file exists $collfile]} {
         return 1
      }
   }
   # is something saved whatever it is?
   return [expr {[llength $args] == 0 && [llength [findCollections]] > 0}]
}

# test at least one of the directories passed as argument is set in MODULEPATH
proc is-used {args} {
   reportDebug $args

   set modpathlist [getModulePathList]
   foreach path $args {
      # transform given path in an absolute path to compare with dirs
      # registered in the MODULEPATH env var which are returned absolute.
      set abspath [getAbsolutePath $path]
      if {[isInList $modpathlist $abspath]} {
         return 1
      }
   }
   # is something used whatever it is?
   return [expr {[llength $args] == 0 && [llength $modpathlist] > 0}]
}

# test at least one of the modulefiles passed as argument exists
proc is-avail {args} {
   reportDebug $args
   set ret 0

   # disable error reporting to avoid modulefile errors
   # to pollute result. Only if not already inhibited
   set alreadyinhibit [isErrorReportInhibited]
   if {!$alreadyinhibit} {
      inhibitErrorReport
   }

   foreach mod $args {
      lassign [getPathToModule $mod] modfile modname
      if {$modfile ne {}} {
         set ret 1
         break
      }
   }

   # re-enable only is it was disabled from this procedure
   if {!$alreadyinhibit} {
      reenableErrorReport
   }
   return $ret
}

########################################################################
# internal module procedures
#
set g_modeStack {}

proc currentMode {} {
   return [lindex $::g_modeStack end]
}

proc pushMode {mode} {
   lappend ::g_modeStack $mode
}

proc popMode {} {
   set ::g_modeStack [lrange $::g_modeStack 0 end-1]
}

set g_moduleNameStack {}

proc currentModuleName {} {
   return [lindex $::g_moduleNameStack end]
}

proc pushModuleName {moduleName} {
   lappend ::g_moduleNameStack $moduleName
}

proc popModuleName {} {
   set ::g_moduleNameStack [lrange $::g_moduleNameStack 0 end-1]
}

# get number of either modulefile/modulerc currently being evaluated
proc getEvalModuleStackDepth {} {
   return [llength $::g_moduleNameStack]
}

set g_moduleFileStack {}

proc pushModuleFile {modfile} {
   lappend ::g_moduleFileStack $modfile
   set ::ModulesCurrentModulefile $modfile
}

proc popModuleFile {} {
   set ::g_moduleFileStack [lrange $::g_moduleFileStack 0 end-1]
   set ::ModulesCurrentModulefile [lindex $::g_moduleFileStack end]
}

set g_specifiedNameStack {}

proc currentSpecifiedName {} {
   return [lindex $::g_specifiedNameStack end]
}

proc pushSpecifiedName {specifiedName} {
   lappend ::g_specifiedNameStack $specifiedName
}

proc popSpecifiedName {} {
   set ::g_specifiedNameStack [lrange $::g_specifiedNameStack 0 end-1]
}

set g_commandNameStack {}

proc currentCommandName {} {
   return [lindex $::g_commandNameStack end]
}

proc aboveCommandName {} {
   return [lindex $::g_commandNameStack end-1]
}

proc pushCommandName {commandName} {
   lappend ::g_commandNameStack $commandName
}

proc popCommandName {} {
   set ::g_commandNameStack [lrange $::g_commandNameStack 0 end-1]
}

# stack of report holder unique identifiers
set g_reportHoldIdStack {}

proc isReportHeld {} {
   return [expr {[llength $::g_reportHoldIdStack] > 0}]
}

proc currentReportHoldId {} {
   return [lindex $::g_reportHoldIdStack end]
}

proc pushReportHoldId {holdid} {
   lappend ::g_reportHoldIdStack $holdid
}

proc popReportHoldId {} {
   set ::g_reportHoldIdStack [lrange $::g_reportHoldIdStack 0 end-1]
}


# stack of message recording unique identifiers
set g_msgRecordIdStack {}

proc currentMsgRecordId {} {
   return [lindex $::g_msgRecordIdStack end]
}

proc topMsgRecordId {} {
   return [lindex $::g_msgRecordIdStack 0]
}

proc pushMsgRecordId {recid} {
   lappend ::g_msgRecordIdStack $recid
}

proc popMsgRecordId {} {
   set ::g_msgRecordIdStack [lrange $::g_msgRecordIdStack 0 end-1]
}

# stack of prefixes clarifying debug message entries
set g_debugMsgPrefixStack {}

proc currentDebugMsgPrefix {} {
   return [lindex $::g_debugMsgPrefixStack end]
}

proc pushDebugMsgPrefix {args} {
   lappend ::g_debugMsgPrefixStack "\[#[join $args :]\] "
}

proc popDebugMsgPrefix {} {
   set ::g_debugMsgPrefixStack [lrange $::g_debugMsgPrefixStack 0 end-1]
}

# gather for the current top evaluation the information on all evaluations
# happening under its umbrella
proc registerModuleEval {context mod {unset 0} {failedcontext {}}} {
   set recid [topMsgRecordId]
   set contextset 0

   # add mod to existing evaluation context list
   if {[info exists ::g_moduleEval($recid)]} {
      for {set i 0} {$i < [llength $::g_moduleEval($recid)]} {incr i 1} {
         set contextevallist [lindex $::g_moduleEval($recid) $i]
         if {[lindex $contextevallist 0] eq $context} {
            if {$unset} {
               set contextevallist [replaceFromList $contextevallist $mod]
            } else {
               lappend contextevallist $mod
            }
            set ::g_moduleEval($recid) [expr {[llength $contextevallist] > 1\
               ? [lreplace $::g_moduleEval($recid) $i $i $contextevallist]\
               : [lreplace $::g_moduleEval($recid) $i $i]}]
            set contextset 1
            break
         }
      }
   }

   # add mod to new evaluation context list
   if {!$unset && !$contextset} {
      lappend ::g_moduleEval($recid) [list $context $mod]
   }

   # add mod to failed evaluation list
   if {$unset} {
      lappend ::g_moduleFailedEval($recid) $failedcontext $mod
   }
}

# get context of currently evaluated module
proc currentModuleEvalContext {} {
   return [lindex $::g_moduleEvalAttempt([currentModuleName]) end]
}

# record module evaluation attempt and corresponding context
proc registerModuleEvalAttempt {context mod} {
   appendNoDupToList ::g_moduleEvalAttempt($mod) $context
}

proc unregisterModuleEvalAttempt {context mod} {
   set ::g_moduleEvalAttempt($mod) [replaceFromList\
      $::g_moduleEvalAttempt($mod) $context]
}

# is at least one module passed as argument evaluated in passed context
proc isModuleEvaluated {context args} {
   set ret 0
   foreach mod $args {
      # get actual module name if mod refers to an alias or symver
      set modres [resolveModuleVersionOrAlias $mod]
      if {[info exists ::g_moduleEvalAttempt($modres)] && ($context eq\
         {any} || [isInList $::g_moduleEvalAttempt($modres) $context])} {
         set ret 1
         break
      }
   }
   return $ret
}

# was passed mod already evaluated for context and failed
proc isModuleEvalFailed {context mod} {
   set ret 0
   set recid [topMsgRecordId]
   if {[info exists ::g_moduleFailedEval($recid)]} {
      foreach {curcon curmod} $::g_moduleFailedEval($recid) {
         if {$context eq $curcon && $mod eq $curmod} {
            set ret 1
            break
         }
      }
   }
   return $ret
}

# stack of flag defining whether a modfile should be always fully read or not
# even for validity check, which is useful in case a file need to be read
# multiple times as a full read will make file content cached thus file will
# be read only once
set g_alwaysReadFullFileStack {}

proc currentAlwaysReadFullFile {} {
   return [lindex $::g_alwaysReadFullFileStack end]
}

proc pushAlwaysReadFullFile {alwaysReadFullFile} {
   lappend ::g_alwaysReadFullFileStack $alwaysReadFullFile
}

proc popAlwaysReadFullFile {} {
   set ::g_alwaysReadFullFileStack [lrange $::g_alwaysReadFullFileStack 0\
      end-1]
}

# return list of currently loading modules in stack
proc getLoadingModuleList {} {
   set modlist [list]
   for {set i 0} {$i < [llength $::g_moduleNameStack]} {incr i 1} {
      if {[lindex $::g_modeStack $i] eq {load}} {
         lappend modlist [lindex $::g_moduleNameStack $i]
      }
   }
   return $modlist
}

# return list of currently loading modulefiles in stack
proc getLoadingModuleFileList {} {
   set modlist [list]
   for {set i 0} {$i < [llength $::g_moduleFileStack]} {incr i 1} {
      if {[lindex $::g_modeStack $i] eq {load}} {
         lappend modlist [lindex $::g_moduleFileStack $i]
      }
   }
   return $modlist
}

# return list of currently unloading modules in stack
proc getUnloadingModuleList {} {
   set modlist [list]
   for {set i 0} {$i < [llength $::g_moduleNameStack]} {incr i 1} {
      if {[lindex $::g_modeStack $i] eq {unload}} {
         lappend modlist [lindex $::g_moduleNameStack $i]
      }
   }
   return $modlist
}
# return list of loaded modules by parsing LOADEDMODULES env variable
proc getLoadedModuleList {{filter_empty 1}} {
   set modlist [list]
   foreach mod [split [get-env LOADEDMODULES] [getPathSeparator]] {
      # ignore empty element
      if {$mod ne {} || !$filter_empty} {
         lappend modlist $mod
      }
   }
   return $modlist
}

# return list of loaded module files by parsing _LMFILES_ env variable
proc getLoadedModuleFileList {} {
   set modfilelist [list]
   foreach modfile [split [get-env _LMFILES_] [getPathSeparator]] {
      # ignore empty element
      if {$modfile ne {}} {
         lappend modfilelist $modfile
      }
   }
   return $modfilelist
}

# return list of loaded module declared conflict by parsing MODULES_LMCONFLICT
proc getLoadedModuleConflictList {} {
   set modconlist [list]
   foreach modconser [split [get-env MODULES_LMCONFLICT] [getPathSeparator]] {
      set conlist [split $modconser $::g_sub1_separator]
      # ignore empty element (1 is meaningless as first elt is loaded mod)
      if {[llength $conlist] > 1} {
         lappend modconlist $conlist
      }
   }
   return $modconlist
}

# return list of loaded module declared prereq by parsing MODULES_LMPREREQ
proc getLoadedModulePrereqList {} {
   set modprelist [list]
   foreach modpreser [split [get-env MODULES_LMPREREQ] [getPathSeparator]] {
      set prelist [split $modpreser $::g_sub1_separator]
      # ignore empty element (1 is meaningless as first elt is loaded mod)
      if {[llength $prelist] > 1} {
         set modpre {}
         foreach pre $prelist {
            lappend modpre [split $pre $::g_sub2_separator]
         }

         lappend modprelist $modpre
      }
   }
   return $modprelist
}

# return list of loaded module asked by user by parsing MODULES_LMNOTUASKED
proc getLoadedModuleNotUserAskedList {} {
   set nuaskedlist [list]
   foreach mod [split [get-env MODULES_LMNOTUASKED] [getPathSeparator]] {
      # ignore empty element
      if {$mod ne {}} {
         lappend nuaskedlist $mod
      }
   }
   return $nuaskedlist
}

# return list of loaded module declared altnames by parsing MODULES_LMALTNAME
proc getLoadedModuleAltnameList {} {
   set modaltlist [list]
   foreach modaltser [split [get-env MODULES_LMALTNAME] [getPathSeparator]] {
      set altlist [split $modaltser $::g_sub1_separator]
      # ignore empty element (1 is meaningless as first elt is loaded mod)
      if {[llength $altlist] > 1} {
         lappend modaltlist $altlist
      }
   }
   return $modaltlist
}

# sort passed module list following both loaded and dependency orders
proc sortModulePerLoadedAndDepOrder {modlist {nporeq 0} {loading 0}} {
   # sort per loaded order
   set sortlist {}
   if {[llength $modlist] > 0} {
      foreach lmmod [getLoadedModuleList] {
         if {[isInList $modlist $lmmod]} {
            lappend sortlist $lmmod
         }
      }
      # also sort eventual loading modules if asked
      if {$loading} {
         foreach loadingmod [lreverse [getLoadingModuleList]] {
            if {[isInList $modlist $loadingmod]} {
               lappend sortlist $loadingmod
            }
         }
      }
   }

   # then refine sort with dependencies between loaded modules: a dependent
   # module should be placed prior the loaded module requiring it
   set reqListVar [expr {$nporeq ? {::g_moduleNPODepend} :\
      {::g_moduleDepend}}]
   set i 0
   set imax [llength $sortlist]
   while {$i < $imax} {
      set mod [lindex $sortlist $i]
      set jmin $imax

      if {[info exists ${reqListVar}($mod)]} {
         # goes over all dependend modules to find the first one in the loaded
         # order list located after requiring mod
         foreach lmmodlist [set ${reqListVar}($mod)] {
            foreach lmmod $lmmodlist {
               set j [lsearch -exact $sortlist $lmmod]
               if {$j > $i && $j < $jmin} {
                  set jmin $j
                  set jminmod $lmmod
               }
            }
         }
      }

      # move first dependent module found after currently inspected mod right
      # before it
      if {$jmin != $imax} {
         set sortlist [linsert [lreplace $sortlist $jmin $jmin] $i $jminmod]
      # or go to next element in list if current element has not been changed
      } else {
         incr i
      }
   }

   return $sortlist
}

# return list of module paths by parsing MODULEPATH env variable
# behavior param enables to exit in error when no MODULEPATH env variable
# is set. by default an empty list is returned if no MODULEPATH set
# resolv_var param tells if environement variable references in path elements
# should be resolved or passed as-is in result list
# set_abs param applies an absolute path name convertion to path elements
# if enabled
proc getModulePathList {{behavior returnempty} {resolv_var 1} {set_abs 1}} {
   if {[info exists ::env(MODULEPATH)]} {
      set modpathlist [list]
      foreach modpath [split $::env(MODULEPATH) [getPathSeparator]] {
         # ignore empty element
         if {$modpath ne {}} {
            if {$resolv_var} {
               set modpath [resolvStringWithEnv $modpath]
            }
            if {$set_abs} {
               set modpath [getAbsolutePath $modpath]
            }
            appendNoDupToList modpathlist $modpath
         }
      }
      return $modpathlist
   } elseif {$behavior eq {exiterronundef}} {
      reportErrorAndExit {No module path defined}
   } else {
      return {}
   }
}

# test if two modules share the same root name
proc isSameModuleRoot {mod1 mod2} {
   set mod1split [split $mod1 /]
   set mod2split [split $mod2 /]

   return [expr {[lindex $mod1split 0] eq [lindex $mod2split 0]}]
}

# test if one element in module name has a leading "dot" making this module
# a hidden module
proc isModuleHidden {mod} {
   foreach elt [split $mod /] {
      if {[string index $elt 0] eq {.}} {
         return 1
      }
   }
   return 0
}

# check if module name is specified as a full pathname (not a name relative
# to a modulepath)
proc isModuleFullPath {mod} {
   return [regexp {^(|\.|\.\.)/} $mod]
}

# check if a module corresponds to a virtual module (module name
# does not corresponds to end of the modulefile name)
proc isModuleVirtual {mod modfile} {
   return [expr {[string first $mod $modfile end-[string length $mod]] == -1}]
}

# Return the full pathname and modulename to the module.  
# Resolve aliases and default versions if the module name is something like
# "name/version" or just "name" (find default version).
proc getPathToModule {mod {indir {}} {look_loaded no} {excdir {}}} {
   reportDebug "finding '$mod' in '$indir' (excdir='$excdir')"

   if {$mod eq {}} {
      set retlist [list {} 0 none {Invalid empty module name}]
   # try first to look at loaded modules if enabled to find maching module
   # or to find a closest match (used when switching with single name arg)
   } elseif {$look_loaded ne {no}} {
      switch -- $look_loaded {
         match {set getLoadedNameProc getLoadedMatchingName}
         close {set getLoadedNameProc getLoadedWithClosestName}
      }
      set retlist [if {[set lm [$getLoadedNameProc $mod]] ne {}} {list\
         [getModulefileFromLoadedModule $lm] $lm} {list {} $mod notloaded}]
   # Check for $mod specified as a full pathname
   } elseif {[isModuleFullPath $mod]} {
      set mod [getAbsolutePath $mod]
      # note that a raw filename as an argument returns the full
      # path as the module name
      lassign [checkValidModule $mod] check_valid check_msg
      switch -- $check_valid {
         true {
            set retlist [list $mod $mod]
         }
         invalid - accesserr {
            set retlist [list {} $mod $check_valid $check_msg $mod]
         }
      }
   } else {
      set dir_list [expr {$indir ne {} ? $indir : [getModulePathList\
         exiterronundef]}]
      # remove excluded directories (already searched)
      foreach dir $excdir {
         set dir_list [replaceFromList $dir_list $dir]
      }

      # modparent is the the modulename minus the module version.
      lassign [getModuleNameVersion $mod] mod modparent modversion
      set modroot [lindex [split $mod /] 0]
      # determine if we need to get hidden modules
      set fetch_hidden [isModuleHidden $mod]

      # Now search for $mod in module paths
      foreach dir $dir_list {
         # get list of modules related to the root of searched module to get
         # in one call a complete list of any module kind (file, alias, etc)
         # related to search to be able to then determine in this proc the
         # correct module to return without restarting new searches
         array unset mod_list
         array set mod_list [getModules $dir $modroot 0 rc_defs_included\
            $fetch_hidden]

         set prevmod {}
         set mod_res {}
         # loop to resolve correct modulefile in case specified mod is a
         # directory that should be analyzed to get default mod in it
         while {$prevmod ne $mod} {
            set prevmod $mod

            if {[info exists mod_list($mod)]} {
               switch -- [lindex $mod_list($mod) 0] {
                  alias - version {
                     set newmod [resolveModuleVersionOrAlias $mod]
                     # continue search on newmod if module from same root and
                     # not hidden (if hidden search disabled) as mod_list
                     # already contains everything related to this root module
                     if {[isSameModuleRoot $mod $newmod] && ($fetch_hidden ||\
                        ![isModuleHidden $newmod])} {
                        set mod $newmod
                        # indicate an alias or a symbol was solved
                        set mod_res $newmod
                     # elsewhere restart search on new modulename, constrained
                     # to specified dir if set
                     } else {
                        return [getPathToModule $newmod $indir]
                     }
                  }
                  directory {
                     # Move to default element in directory
                     set mod $mod/[lindex $mod_list($mod) 1]
                     # restart search if default element is hidden and hidden
                     # elements were not searched
                     if {!$fetch_hidden && [isModuleHidden $mod]} {
                        return [getPathToModule $mod $indir]
                     }
                  }
                  modulefile {
                     # If mod was a file in this path, return that file
                     set retlist [list $dir/$mod $mod]
                  }
                  virtual {
                     # return virtual name with file it targets
                     set retlist [list [lindex $mod_list($mod) 2] $mod]
                  }
                  invalid - accesserr {
                     # may found mod but issue, so end search with error
                     set retlist [concat [list {} $mod] $mod_list($mod)]
                  }
               }
            }
         }
         # break loop if found something (valid or invalid module)
         # elsewhere go to next path
         if {[info exists retlist]} {
            break
         # found nothing after solving a matching alias or symbol
         } elseif {$mod_res eq $mod} {
            lappend excdir $dir
            # look for this name in the other module paths, so restart
            # directory search from first dir in list to ensure precedence
            return [getPathToModule $mod $indir no $excdir]
         }
      }
   }

   # set result if nothing found
   if {![info exists retlist]} {
      set retlist [list {} $mod none "Unable to locate a modulefile for\
         '$mod'"]
   }
   if {[lindex $retlist 0] ne {}} {
      reportDebug "found '[lindex $retlist 0]' as '[lindex $retlist 1]'"
   # no error if we look at loaded modules and passed mod not found loaded
   } elseif {[lindex $retlist 2] ne {notloaded}} {
      eval reportIssue [lrange $retlist 2 4]
   }
   return $retlist
}

proc isModuleLoaded {mod} {
   cacheCurrentModules

   return [info exists ::g_loadedModules($mod)]
}

proc getModulefileFromLoadedModule {mod} {
   if {[isModuleLoaded $mod]} {
      return $::g_loadedModules($mod)
   } else {
      return {}
   }
}

proc isModulefileLoaded {modfile} {
   cacheCurrentModules

   return [info exists ::g_loadedModuleFiles($modfile)]
}

proc getModuleFromLoadedModulefile {modfile {idx all}} {
   set ret {}

   if {[isModulefileLoaded $modfile]} {
      set ret [expr {$idx eq {all} ? $::g_loadedModuleFiles($modfile) :\
         [lindex $::g_loadedModuleFiles($modfile) $idx]}]
   }

   return $ret
}

proc isModuleLoading {mod} {
   return [isInList [getLoadingModuleList] $mod]
}

proc isModulefileLoading {modfile} {
   return [isInList [getLoadingModuleFileList] $modfile]
}

proc getModuleFromLoadingModulefile {modfile {idx all}} {
   set ret {}

   if {[isModulefileLoading $modfile]} {
      set loadingmodlist [getLoadingModuleList]
      foreach i [lsearch -all -exact [getLoadingModuleFileList] $modfile] {
         lappend modlist [lindex $loadingmodlist $i]
      }

      set ret [expr {$idx eq {all} ? $modlist : [lindex $modlist $idx]}]
   }

   return $ret
}

proc setLoadedModule {mod modfile uasked} {
   set ::g_loadedModules($mod) $modfile
   # a loaded modfile may correspond to multiple loaded virtual modules
   lappend ::g_loadedModuleFiles($modfile) $mod
   # record if mod has been asked by user
   if {$uasked} {
      set ::g_loadedModuleUasked($mod) 1
   }
   # build dependency chain
   setModuleDependency $mod
}

proc unsetLoadedModule {mod modfile} {
   unset ::g_loadedModules($mod)
   # a loaded modfile may correspond to multiple loaded virtual modules
   if {[llength $::g_loadedModuleFiles($modfile)] == 1} {
      unset ::g_loadedModuleFiles($modfile)
   } else {
      set ::g_loadedModuleFiles($modfile) [replaceFromList\
         $::g_loadedModuleFiles($modfile) $mod]
   }
   if {[info exists ::g_loadedModuleUasked($mod)]} {
      unset ::g_loadedModuleUasked($mod)
   }
   # update dependencies
   unsetModuleDependency $mod
}

# check if name matches passed mod name or one of its alternative name
proc doesModuleMatchesName {mod name} {
   cacheCurrentModules
   set ret 0
   # check if main or alternative names of loaded mod matches passed name
   foreach matchmod [concat [list $mod] [getLoadedAltname $mod]] {
      if {[string first $name/ $matchmod/] == 0} {
         set ret 1
         break
      }
   }
   return $ret
}

# check if name matches one name of passed loading mod (main or alternative)
proc doesLoadingModuleMatchesName {mod name} {
   set ret 0
   # check if main or alternative names of loading mod matches passed name
   # directly look at all resolved names structure as alternative names for
   # loading modules are not yet registered elsewhere
   foreach matchmod [concat [list $mod] [getAllModuleResolvedName $mod]] {
      if {[string first $name/ $matchmod/] == 0} {
         set ret 1
         break
      }
   }
   return $ret
}

# return the currently loaded module whose name is the closest to the
# name passed as argument. if no loaded module match at least one part
# of the passed name, an empty string is returned.
proc getLoadedWithClosestName {name} {
   set ret {}
   set retmax 0

   if {[isModuleFullPath $name]} {
      set fullname [getAbsolutePath $name]
      # if module is passed as full modulefile path name, get corresponding
      # short name from used modulepaths
      if {[set shortname [findModuleNameFromModulefile $fullname]] ne {}} {
         set namesplit [split $shortname /]
      # or look at lmfile names to return the eventual exact match
      } else {
         # module may be loaded with its full path name
         if {[isModuleLoaded $fullname]} {
            set ret $fullname
         # or name corresponds to the _lmfiles_ entry of a virtual modules in
         # which case lastly loaded virtual module is returned
         } elseif {[isModulefileLoaded $fullname]} {
            set ret [getModuleFromLoadedModulefile $fullname end]
         }
      }
   } else {
      set namesplit [split $name /]
   }

   if {[info exists namesplit]} {
      # compare name to each currently loaded module name
      foreach mod [getLoadedModuleList] {
         # if module loaded as fullpath but test name not, try to get loaded
         # mod short name (with currently used modulepaths) to compare it
         if {[isModuleFullPath $mod] && [set modname\
            [findModuleNameFromModulefile $mod]] ne {}} {
            # no alt name to retrieve if module has been loaded full path
            set matchmodlist [list $modname]
         } else {
            # add alternative names of mod to the matching list
            set matchmodlist [concat [list $mod] [getLoadedAltname $mod]]
         }

         foreach matchmod $matchmodlist {
            set modsplit [split $matchmod /]
            # min expr function is not supported in Tcl8.4 and earlier
            set imax [if {[llength $namesplit] < [llength $modsplit]}\
               {llength $namesplit} {llength $modsplit}]

            # compare each element of the name to find closest answer
            # in case of equality, last loaded module will be returned as it
            # overwrites previously found value
            for {set i 0} {$i < $imax} {incr i} {
               if {[lindex $modsplit $i] eq [lindex $namesplit $i]} {
                  if {$i >= $retmax} {
                     set retmax $i
                     set ret $mod
                  }
               } else {
                  # end of match, go next mod
                  break
               }
            }
         }
      }
   }

   reportDebug "'$ret' closest to '$name'"
   return $ret
}

# return the currently loaded module whose name is equal or include the name
# passed as argument. if no loaded module match, an empty string is returned.
# loading: look at currently loading modules instead of loaded if loading == 1
# lmlist: only take into account passed loaded module list not all loaded mods
proc getLoadedMatchingName {name {behavior returnlast} {loading 0} {lmlist\
   {}}} {
   set ret {}
   set retmax 0

   # use loading-specific procedures instead of loaded-specific ones
   if {$loading} {
      set isModulefileLoaded isModulefileLoading
      set getModuleFromLoadedModulefile getModuleFromLoadingModulefile
      set getLoadedModuleList getLoadingModuleList
      set doesModuleMatchesName doesLoadingModuleMatchesName
   } else {
      set isModulefileLoaded isModulefileLoaded
      set getModuleFromLoadedModulefile getModuleFromLoadedModulefile
      set getLoadedModuleList getLoadedModuleList
      set doesModuleMatchesName doesModuleMatchesName
   }

   # fetch currently loaded/loading module name is no list provided
   if {[llength $lmlist] == 0} {
      set lmlist [$getLoadedModuleList]
   }

   # if module is passed as full modulefile path name, look at lmfile names
   # to return the eventual exact match
   if {[isModuleFullPath $name]} {
      set mod [getAbsolutePath $name]
      # if module is loaded with its full path name loadedmodules entry is
      # equivalent to _lmfiles_ corresponding entry so only check _lmfiles_
      if {[$isModulefileLoaded $mod]} {
         # a loaded modfile may correspond to multiple loaded virtual modules
         switch -- $behavior {
            returnlast {
               # the last loaded/loading module will be returned
               set ret [$getModuleFromLoadedModulefile $mod end]
            }
            returnfirst {
               # the first loaded/loading module will be returned
               set ret [$getModuleFromLoadedModulefile $mod 0]
            }
            returnall {
               # all loaded/loading modules will be returned
               set ret [$getModuleFromLoadedModulefile $mod]
            }
         }
      }
   } elseif {$name ne {}} {
      # compare name to each currently loaded/loading module name, if multiple
      # mod match name:
      foreach mod $lmlist {
         # if module loaded as fullpath but test name not, try to get loaded
         # mod short name (with currently used modulepaths) to compare it
         if {[isModuleFullPath $mod] && [set modname\
            [findModuleNameFromModulefile $mod]] ne {}} {
            set matchmod $modname
         } else {
            set matchmod $mod
         }
         if {[$doesModuleMatchesName $matchmod $name]} {
            switch -- $behavior {
               returnlast {
                  # the last loaded module will be returned
                  set ret $mod
               }
               returnfirst {
                  # the first loaded module will be returned
                  set ret $mod
                  break
               }
               returnall {
                  # all loaded modules will be returned
                  lappend ret $mod
               }
            }
         }
      }
   }

   reportDebug "'$ret' matches '$name'"
   return $ret
}

proc setLoadedConflict {mod args} {
   eval appendNoDupToList ::g_loadedModuleConflict($mod) $args
}

proc unsetLoadedConflict {mod} {
   if {[info exists ::g_loadedModuleConflict($mod)]} {
      unset ::g_loadedModuleConflict($mod)
   }
}

proc getLoadedConflict {mod {serialized 0}} {
   set ret {}

   if {[info exists ::g_loadedModuleConflict($mod)]} {
      if {$serialized} {
         # get conflict info as a string that can be registered in an env var
         set ret [join [concat [list $mod] $::g_loadedModuleConflict($mod)]\
            $::g_sub1_separator]
      } else {
         set ret $::g_loadedModuleConflict($mod)
      }
   }

   return $ret
}

proc doesModuleConflict {mod} {
   set does 0
   set modconlist {}
   set moddecconlist {}

   # check if any loaded module has declared a conflict
   foreach modcon [array names ::g_loadedModuleConflict] {
      # look if some loaded or loading modules correspond to conflict defined
      # by mod
      if {$modcon eq $mod} {
         foreach withmod $::g_loadedModuleConflict($modcon) {
            # skip own reflexive conflict (look at mod main and alternative
            # names) and those already known
            if {![doesModuleMatchesName $mod $withmod] && ([set lmmod\
               [getLoadedMatchingName $withmod returnfirst]] ne {} || [set\
               lmmod [getLoadedMatchingName $withmod returnfirst 1]] ne {})} {
               appendNoDupToList modconlist $lmmod
               # also collect conflict declared name
               appendNoDupToList moddecconlist $withmod
               set does 1
            }
         }
      # other loaded module declared conflicts (skipping those already known)
      } elseif {[notInList $modconlist $modcon]} {
         foreach withmod $::g_loadedModuleConflict($modcon) {
            # check if mod or one of its alt name match conflict
            if {[doesModuleMatchesName $mod $withmod]} {
               lappend modconlist $modcon
               lappend moddecconlist $modcon
               set does 1
               break
            }
         }
      }
   }

   reportDebug "'$mod' conflicts with '$modconlist' (declared as '$moddecconlist')"
   return [list $does $modconlist $moddecconlist]
}

proc setLoadedPrereq {mod args} {
   eval appendNoDupToList ::g_loadedModulePrereq($mod) $args
}

proc unsetLoadedPrereq {mod} {
   if {[info exists ::g_loadedModulePrereq($mod)]} {
      unset ::g_loadedModulePrereq($mod)
   }
}

proc getLoadedPrereq {mod {serialized 0}} {
   set ret {}

   if {[info exists ::g_loadedModulePrereq($mod)]} {
      if {$serialized} {
         # get prereq info as a string that can be registered in an env var
         foreach pre $::g_loadedModulePrereq($mod) {
            lappend modpre [join $pre $::g_sub2_separator]
         }
         set ret [join [concat [list $mod] $modpre] $::g_sub1_separator]
      } else {
         set ret $::g_loadedModulePrereq($mod)
      }
   }

   return $ret
}

proc setLoadedAltname {mod args} {
   eval appendNoDupToList ::g_loadedModuleAltname($mod) $args
}

proc unsetLoadedAltname {mod} {
   if {[info exists ::g_loadedModuleAltname($mod)]} {
      unset ::g_loadedModuleAltname($mod)
   }
}

proc getLoadedAltname {mod {serialized 0}} {
   set ret {}

   if {[info exists ::g_loadedModuleAltname($mod)]} {
      if {$serialized} {
         # get altname info as a string that can be registered in an env var
         set ret [join [concat [list $mod] $::g_loadedModuleAltname($mod)]\
            $::g_sub1_separator]
      } else {
         set ret $::g_loadedModuleAltname($mod)
      }
   }

   return $ret
}

proc isModuleUserAsked {mod} {
   cacheCurrentModules

   return [info exists ::g_loadedModuleUasked($mod)]
}

# register conflict violation state between loaded modules
proc setModuleConflictViolation {mod modconlist} {
   reportDebug "set conflict violation state for '$mod'"
   set ::g_conflictViolation($mod) $modconlist
   # also update violation state for loaded mod conflicting with mod
   foreach lmmod $modconlist {
      if {[appendNoDupToList ::g_conflictViolation($lmmod) $mod]} {
         reportDebug "set/update conflict violation state for '$lmmod'"
      }
   }
}

# unregister conflict violation state between modules
proc unsetModuleConflictViolation {mod} {
   if {[info exists ::g_conflictViolation($mod)]} {
      # also update violation state for loaded mod conflicting with mod
      foreach lmmod $::g_conflictViolation($mod) {
         set convio [replaceFromList\
            $::g_conflictViolation($lmmod) $mod]
         reportDebug "unset/update conflict violation state for '$lmmod'"
         if {[llength $convio] == 0} {
            unset ::g_conflictViolation($lmmod)
         } else {
            set ::g_conflictViolation($lmmod) $convio
         }
      }
      reportDebug "unset conflict violation state for '$mod'"
      unset ::g_conflictViolation($mod)
   }
}

# build dependency chain between loaded modules based on registered prereqs
proc setModuleDependency {mod} {
   set modlist [getLoadedModuleList]
   # only look at modules loaded prior current one to find requirements,
   # modules loaded afterward are unmet dependencies as dependents have
   # not been reloaded after them
   set modidx [lsearch -exact $modlist $mod]
   set modnpolist [lrange $modlist [expr {$modidx + 1}] end]
   # reverse list to get closest match
   set modlist [lreverse [lrange $modlist 0 $modidx]]
   set deplist {}
   set depnpolist {}

   foreach prereq [getLoadedPrereq $mod] {
      # get corresponding loaded module for each element of the prereq order
      set lmprelist {}
      set lmnpolist {}
      foreach modpre $prereq {
         set lmfound {}
         foreach lmmod $modlist {
            if {[doesModuleMatchesName $lmmod $modpre]} {
               set lmfound $lmmod
               break
            }
         }

         # register an unmet dependency/requirement if no loaded mod matches
         if {$lmfound eq {}} {
            reportDebug "set an unmet requirement on '$modpre' for '$mod'"
            lappend ::g_moduleUnmetDep($mod) $modpre
            lappend ::g_unmetDepHash($modpre) $mod
         # add matching mod elsewhere
         } else {
            appendNoDupToList lmprelist $lmfound
            appendNoDupToList lmnpolist $lmfound
         }

         # look if requirement can be found in the No Particular Order list
         foreach lmmod $modnpolist {
            if {[doesModuleMatchesName $lmmod $modpre]} {
               appendNoDupToList lmnpolist $lmmod
               break
            }
         }
      }

      switch -- [llength $lmprelist] {
         0 {
            # prereq not satisfied
            reportDebug "set prereq violation state for '$mod'"
            lappend ::g_prereqViolation($mod) $prereq
         }
         1 {
            set lmmod [lindex $lmprelist 0]
            lappend deplist $lmmod
            # set 'is depended by' relations
            lappend ::g_dependHash($lmmod) $mod
         }
         default {
            lappend deplist $lmprelist
            # many modules in prereq list, means they all set an optional dep
            foreach lmmod $lmprelist {
               lappend ::g_dependHash($lmmod) [list $mod 1]
            }
         }
      }

      # build 'is depended by' relations not taking loading order into account
      switch -- [llength $lmnpolist] {
         0 {
            # even on No Particular Order mode, prereq is not satisfied
            reportDebug "set NPO prereq violation state for '$mod'"
            lappend ::g_prereqNPOViolation($mod) $prereq
         }
         1 {
            set lmmod [lindex $lmnpolist 0]
            lappend depnpolist $lmmod
            # set 'is depended by' relations
            lappend ::g_dependNPOHash($lmmod) $mod
         }
         default {
            lappend depnpolist $lmnpolist
            # many modules in prereq list, means they all set an optional dep
            foreach lmmod $lmnpolist {
               lappend ::g_dependNPOHash($lmmod) [list $mod 1]
            }
         }
      }
   }

   # conflict not satisfied
   lassign [doesModuleConflict $mod] doescon modconlist
   if {$doescon} {
      setModuleConflictViolation $mod $modconlist
   }

   # update eventual registered unmet dependencies
   foreach modpre [array names ::g_unmetDepHash] {
      if {[doesModuleMatchesName $mod $modpre]} {
         reportDebug "refresh requirements targetting '$modpre'"
         foreach lmmod $::g_unmetDepHash($modpre) {
            if {[isInList [getDependentLoadedModuleList $lmmod 0 0] $mod]} {
               reportDebug "skip deps refresh for '$lmmod' as dep cycle\
                  detected with '$mod'"

               # remove dependency link in no particular order structs to
               # avoid cycle first in 'is depended by' struct
               if {[info exists ::g_dependNPOHash($mod)]} {
                  set depmodlist $::g_dependNPOHash($mod)
                  for {set i 0} {$i < [llength $depmodlist]} {incr i 1} {
                     if {[lindex [lindex $depmodlist $i] 0] eq $lmmod} {
                        set depmodlist [lreplace $depmodlist $i $i]
                        break
                     }
                  }
                  set ::g_dependNPOHash($mod) $depmodlist
                  reportDebug "update NPO dependent of '$mod' to\
                     '$depmodlist'"
               }
               # then update 'depend on' struct
               set lmmoddepnpolist {}
               foreach depmodlist $::g_moduleNPODepend($lmmod) {
                  if {[set depidx [lsearch -exact $depmodlist $mod]] != -1} {
                     set depmodlist [lreplace $depmodlist $depidx $depidx]
                     # implies to update consistenly alternate requirement or
                     # violation state if no alternative loaded
                     switch -- [llength $depmodlist] {
                        0 {
                           # do not know exact prereq name, so use correspond.
                           # loaded module matching it
                           lappend ::g_prereqNPOViolation($lmmod) $mod
                           reportDebug "set NPO prereq violation state for\
                              '$lmmod'"
                        }
                        1 {
                           # update alternate loaded mod which became a strong
                           # requirement
                           set altmod [lindex $depmodlist 0]
                           set ::g_dependNPOHash($altmod) [replaceFromList\
                              $::g_dependNPOHash($altmod) [list $lmmod 1]\
                              $lmmod]
                           reportDebug "update NPO dependent of '$altmod' to\
                              '$::g_dependNPOHash($altmod)'"
                        }
                     }
                  }
                  lappend lmmoddepnpolist $depmodlist
               }
               reportDebug "update NPO requirement of '$lmmod' to\
                  '$lmmoddepnpolist'"
               set ::g_moduleNPODepend($lmmod) $lmmoddepnpolist
            } else {
               # refresh actual dependencies of targetting mod
               unsetModuleDependency $lmmod
               setModuleDependency $lmmod
            }
         }
      }
   }

   # set 'depends on' relation
   reportDebug "set requirements of '$mod' to '$deplist'"
   set ::g_moduleDepend($mod) $deplist
   reportDebug "set NPO requirements of '$mod' to '$depnpolist'"
   set ::g_moduleNPODepend($mod) $depnpolist
}

# update dependency chain when unloading module
proc unsetModuleDependency {mod} {
   foreach lmmodlist $::g_moduleDepend($mod) {
      set manymod [expr {[llength $lmmodlist] > 1 ? 1 : 0}]

      # unset 'is depended by' mod relations
      foreach lmmod $lmmodlist {
         if {[info exists ::g_dependHash($lmmod)]} {
            set hashdep [expr {$manymod ? [list $mod 1] : $mod}]
            set ::g_dependHash($lmmod) [replaceFromList\
               $::g_dependHash($lmmod) $hashdep]
            if {[llength $::g_dependHash($lmmod)] == 0} {
               unset ::g_dependHash($lmmod)
            }
         }
      }
   }
   # unset mod's 'depends on' relation
   reportDebug "unset requirements of '$mod'"
   unset ::g_moduleDepend($mod)

   foreach lmmodlist $::g_moduleNPODepend($mod) {
      set manymod [expr {[llength $lmmodlist] > 1 ? 1 : 0}]

      # unset 'is depended by' mod relations
      foreach lmmod $lmmodlist {
         if {[info exists ::g_dependNPOHash($lmmod)]} {
            set hashdep [expr {$manymod ? [list $mod 1] : $mod}]
            set ::g_dependNPOHash($lmmod) [replaceFromList\
               $::g_dependNPOHash($lmmod) $hashdep]
            if {[llength $::g_dependNPOHash($lmmod)] == 0} {
               unset ::g_dependNPOHash($lmmod)
            }
         }
      }
   }
   # unset mod's No Particular Order 'depends on' relation
   reportDebug "unset NPO requirements of '$mod'"
   unset ::g_moduleNPODepend($mod)

   # unset eventual violation states
   if {[info exists ::g_prereqViolation($mod)]} {
      reportDebug "unset prereq violation state for '$mod'"
      unset ::g_prereqViolation($mod)
   }
   if {[info exists ::g_prereqNPOViolation($mod)]} {
      reportDebug "unset NPO prereq violation state for '$mod'"
      unset ::g_prereqNPOViolation($mod)
   }
   unsetModuleConflictViolation $mod

   # unset eventual registered unmet dependencies
   if {[info exists ::g_moduleUnmetDep($mod)]} {
      foreach ummod $::g_moduleUnmetDep($mod) {
         if {[info exists ::g_unmetDepHash($ummod)]} {
            set ::g_unmetDepHash($ummod) [replaceFromList\
               $::g_unmetDepHash($ummod) $mod]
            if {[llength $::g_unmetDepHash($ummod)] == 0} {
               unset ::g_unmetDepHash($ummod)
            }
         }
      }
      reportDebug "unset unmet requirements for '$mod'"
      unset ::g_moduleUnmetDep($mod)
   }

   # unset mod's 'is depended by' relations
   set hashdeplist [getDirectDependentList $mod]
   if {[llength $hashdeplist] > 0} {
      reportDebug "refresh dependent of '$mod'"
      foreach lmmod $hashdeplist {
         # refresh actual dependencies of targetting mod
         unsetModuleDependency $lmmod
         setModuleDependency $lmmod
      }
   }
}

# returns if any loaded module (if passed mod is empty) or passed mod and all
# its requirement chain satisfy their loading constraints (prereq & conflict)
proc areModuleConstraintsSatisfied {{mod {}} {nporeq 0}} {
   set ret 1
   cacheCurrentModules

   # are requirements loaded after their dependent included or not
   if {$nporeq} {
      set reqVioVar ::g_prereqNPOViolation
      set reqListVar ::g_moduleNPODepend
   } else {
      set reqVioVar ::g_prereqViolation
      set reqListVar ::g_moduleDepend
   }

   # check if any loaded module violates its prereq or conflict constraints
   if {$mod eq {}} {
      if {[array size ::g_conflictViolation] > 0 || [array size\
         $reqVioVar] > 0} {
         set ret 0
      }
   } else {
      set fulllist [list $mod]
      for {set i 0} {$i < [llength $fulllist]} {incr i 1} {
         set depmod [lindex $fulllist $i]

         # check if depmod violates its prereq or conflict constraints
         if {[info exists ::g_conflictViolation($depmod)] || [info exists\
            ${reqVioVar}($depmod)]} {
            # found violation among the requirement chain of mod so the
            # constraint of mod are not satisfied
            set ret 0
            break
         }
         # add requirements of depmod to the module to check list
         foreach lmmodlist [set ${reqListVar}($depmod)] {
            eval appendNoDupToList fulllist $lmmodlist
         }
      }
   }

   return $ret
}

# return list of loaded modules having an unmet requirement on passed mod
# and their recursive dependent
proc getUnmetDependentLoadedModuleList {mod} {
   reportDebug "get dependent of upcoming loaded '$mod'"
   set unmetdeplist {}
   set depmodlist {}

   # skip dependent analysis if mod has a conflict with a loaded module
   lassign [doesModuleConflict $mod] doescon modconlist
   if {!$doescon} {
      foreach ummod [array names ::g_unmetDepHash] {
         if {[doesModuleMatchesName $mod $ummod]} {
            foreach depmod $::g_unmetDepHash($ummod) {
               lappend depmodlist $depmod
               # temporarily remove prereq violation of depmod if mod
               # load solves it (no other prereq is missing)
               if {[info exists ::g_prereqViolation($depmod)]} {
                  foreach prereq $::g_prereqViolation($depmod) {
                     foreach modpre $prereq {
                        # also temporarily remove prereq violation for
                        # requirements loaded after dependent module
                        if {[doesModuleMatchesName $mod $modpre] ||\
                           [is-loaded $modpre]} {
                           # backup original violation to restore it later
                           if {![info exists preunvioarr($depmod)]} {
                              set preunvioarr($depmod)\
                                 $::g_prereqViolation($depmod)
                           }
                           # temporarily remove matching violation
                           set ::g_prereqViolation($depmod) [replaceFromList\
                              $::g_prereqViolation($depmod) $prereq]
                           if {[llength $::g_prereqViolation($depmod)] == 0} {
                              unset ::g_prereqViolation($depmod)
                           }
                           break
                        }
                     }
                  }
               }
            }
         }
      }
   }

   # select dependent if all its constraint are now satisfied (after removing
   # eventual prereq violation toward mod)
   foreach depmod $depmodlist {
      if {[areModuleConstraintsSatisfied $depmod]} {
         appendNoDupToList unmetdeplist $depmod
      }
   }

   # get dependent of dependent
   set deplist [getDependentLoadedModuleList $unmetdeplist 0 0 0 0 1]

   # restore temporarily lift prereq violation
   if {[array exists preunvioarr]} {
      foreach depmod [array names preunvioarr] {
         set ::g_prereqViolation($depmod) $preunvioarr($depmod)
      }
   }

   set sortlist [sortModulePerLoadedAndDepOrder [concat $unmetdeplist\
      $deplist]]
   reportDebug "got '$sortlist'"
   return $sortlist
}

# return list of loaded modules declaring a prereq on passed mod with
# distinction made with strong prereqs (no alternative loaded) or weak and
# also with prereq loaded after their dependent module
proc getDirectDependentList {mod {strong 0} {nporeq 0} {loading 0}\
   {othmodlist {}}} {
   set deplist {}

   # include or not requirements loaded after their dependent
   if {$nporeq} {
      set depListVar ::g_dependNPOHash
      set reqListVar ::g_moduleNPODepend
   } else {
      set depListVar ::g_dependHash
      set reqListVar ::g_moduleDepend
   }

   if {[info exists ${depListVar}($mod)]} {
      foreach depmod [set ${depListVar}($mod)] {
         set add 1
         # skip optional dependency if only looking for strong ones
         # look at an additionally processed mod list to determine if all
         # mods from a dependent list (composed of optional parts) are part
         # of the search, which means mod is not optional but strong dependent
         if {$strong && [llength $depmod] > 1} {
            foreach lmmodlist [set ${reqListVar}([lindex $depmod 0])] {
               if {[isInList $lmmodlist $mod]} {
                  foreach lmmod $lmmodlist {
                     # other mod part of the opt list is not there so mod
                     # is considered optional
                     if {[notInList $othmodlist $lmmod]} {
                        set add 0
                        break
                     }
                  }
                  break
               }
            }
         }

         if {$add} {
            lappend deplist [lindex $depmod 0]
         }
      }
   }

   # take currently loading modules into account if asked
   if {$loading} {
      # reverse list to get closest match
      set modlist [lreverse [getLoadedModuleList]]
      foreach loadingmod [getLoadingModuleList] {
         foreach prereq [getLoadedPrereq $loadingmod] {
            set lmprelist {}
            set moddep 0
            foreach modpre $prereq {
               foreach lmmod $modlist {
                  if {[doesModuleMatchesName $lmmod $modpre]} {
                     lappend lmprelist $lmmod
                     if {$lmmod eq $mod} {
                        set moddep 1
                     }
                     break
                  }
               }
            }
            if {$moddep && (!$strong || [llength $lmprelist] == 1)} {
               lappend deplist $loadingmod
               break
            }
         }
      }
   }

   return $deplist
}

# gets the list of all loaded modules which are dependent of passed modlist
# ordered by load position. strong argument controls whether only the active
# dependent modules should be returned or also those that are optional. direct
# argument controls if only dependent module directly requiring passed mods
# should be returned or its full dependent tree. nporeq argument tells if
# requirement loaded after their dependent should be returned. sat_constraint
# argument controls whether only the loaded module satisfying their constraint
# should be part or not of the resulting list. being_unload argument controls
# whether loaded modules in conflict with one or multiple modules from modlist
# should be added to the dependent list as these modules are currently being
# unloaded and these conflicting loaded modules should be refreshed.
proc getDependentLoadedModuleList {modlist {strong 1} {direct 1} {nporeq 0}\
   {loading 1} {sat_constraint 0} {being_unload 0}} {
   reportDebug "get loaded mod dependent of '$modlist' (strong=$strong,\
      direct=$direct, nporeq=$nporeq, loading=$loading,\
      sat_constraint=$sat_constraint, being_unload=$being_unload)"

   set deplist {}
   set fulllist $modlist
   # look at consistent requirements for unloading modules
   set unlonporeq [expr {$being_unload ? 0 : $nporeq}]
   foreach mod $modlist {
      # no duplicates or modules from query list
      eval appendNoDupToList fulllist [getDirectDependentList $mod $strong\
         $unlonporeq $loading $fulllist]
   }

   if {$being_unload} {
      # invite modules in violation with mods to be part of the dependent list
      # with their own dependent modules as mod is being unloaded. Achieve so
      # by faking that conflict violation is gone
      foreach mod $modlist {
         lassign [doesModuleConflict $mod] doescon modconlist
         if {$doescon} {
            unsetModuleConflictViolation $mod
            set conunvioarr($mod) $modconlist
            eval appendNoDupToList fulllist $modconlist
         }
      }
   }
   set unloadingmodlist [getUnloadingModuleList]
   for {set i [llength $modlist]} {$i < [llength $fulllist]} {incr i 1} {
      set depmod [lindex $fulllist $i]

      # skip already added mod or mod violating constraints if asked
      if {!$sat_constraint || [areModuleConstraintsSatisfied $depmod\
         $nporeq]} {
         # get dependent mod of dep mod when looking at full dep tree
         if {!$direct} {
            eval appendNoDupToList fulllist [getDirectDependentList $depmod\
               $strong $nporeq 0 $fulllist]
         }
         # avoid module currently unloading from result list
         if {[notInList $unloadingmodlist $depmod]} {
            lappend deplist $depmod
         }
      }
   }

   # restore conflict violation if any
   if {[array exists conunvioarr]} {
      foreach conunvio [array names conunvioarr] {
         setModuleConflictViolation $conunvio $conunvioarr($conunvio)
      }
   }

   # sort complete result list to match both loaded and dependency orders
   set sortlist [sortModulePerLoadedAndDepOrder $deplist $nporeq $loading]
   reportDebug "got '$sortlist'"
   return $sortlist
}

# test if passed 'mod' could be automatically unloaded or not, which means it
# has been loaded automatically and no loaded modules require it anymore.
# unmodlist: pass a list of modules that are going to be unloaded
proc isModuleUnloadable {mod {unmodlist {}}} {
   set ret 1
   # get currently unloading modules if no specific unmodlist set
   if {[llength $unmodlist] == 0} {
      set unmodlist [getUnloadingModuleList]
   }

   if {[isModuleUserAsked $mod]} {
      set ret 0
   } else {
      # mod is unloadable if all its dependent are unloaded or unloading
      foreach depmod [getDirectDependentList $mod] {
         if {[notInList $unmodlist $depmod]} {
            set ret 0
            break
         }
      }
   }

   return $ret
}

# gets the list of all loaded modules which are required by passed modlist
# ordered by load position.
proc getRequiredLoadedModuleList {modlist} {
   reportDebug "get mods required by '$modlist'"

   # search over all list of loaded modules, starting with passed module
   # list, then adding in turns their requirements
   set fulllist $modlist
   for {set i 0} {$i < [llength $fulllist]} {incr i 1} {
      # gets the list of loaded modules which are required by depmod
      eval appendNoDupToList fulllist $::g_moduleDepend([lindex $fulllist $i])
   }

   # sort complete result list to match both loaded and dependency orders
   set sortlist [sortModulePerLoadedAndDepOrder [lrange $fulllist [llength\
      $modlist] end]]
   reportDebug "got '$sortlist'"
   return $sortlist
}

# finds required modules that can be unloaded if passed modules are unloaded:
# they have been loaded automatically and are not depended (mandatory or
# optionally) by other module
proc getUnloadableLoadedModuleList {modlist} {
   reportDebug "get unloadable mods once '$modlist' unloaded"

   # search over all list of unloaded modules, starting with passed module
   # list, then adding in turns unloadable requirements
   set fulllist $modlist
   for {set i 0} {$i < [llength $fulllist]} {incr i 1} {
      set depmod [lindex $fulllist $i]
      # gets the list of loaded modules which are required by depmod
      set deplist {}
      foreach lmmodlist $::g_moduleDepend($depmod) {
         foreach lmmod $lmmodlist {
            if {[notInList $fulllist $lmmod]} {
               lappend deplist $lmmod
            }
         }
      }

      # get those required module that have been automatically loaded and are
      # only required by modules currently being unloaded
      foreach lmmod $deplist {
         if {[isModuleUnloadable $lmmod $fulllist]} {
            lappend fulllist $lmmod
         }
      }
   }

   # sort complete result list to match both loaded and dependency orders
   set sortlist [sortModulePerLoadedAndDepOrder [lrange $fulllist [llength\
      $modlist] end]]
   reportDebug "got '$sortlist'"
   return $sortlist
}

# runs the global RC files if they exist
proc runModulerc {} {
   set rclist {}

   reportDebug running...

   if {[info exists ::env(MODULERCFILE)]} {
      # if MODULERCFILE is a dir, look at a modulerc file in it
      if {[file isdirectory $::env(MODULERCFILE)]\
         && [file isfile $::env(MODULERCFILE)/modulerc]} {
         lappend rclist $::env(MODULERCFILE)/modulerc
      } elseif {[file isfile $::env(MODULERCFILE)]} {
         lappend rclist $::env(MODULERCFILE)
      }
   }
   if {[file isfile @prefix@/etc/rc]} {
      lappend rclist @prefix@/etc/rc
   }
   if {[info exists ::env(HOME)] && [file isfile $::env(HOME)/.modulerc]} {
      lappend rclist $::env(HOME)/.modulerc
   }

   foreach rc $rclist {
      if {[file readable $rc]} {
         reportDebug "Executing $rc"
         cmdModuleSource $rc
         lappend ::g_rc_loaded $rc
      }
   }

   # identify alias or symbolic version set in these global RC files to be
   # able to include them or not in output or resolution processes
   array set ::g_rcAlias [array get ::g_moduleAlias]
   array set ::g_rcVersion [array get ::g_moduleVersion]
   array set ::g_rcVirtual [array get ::g_moduleVirtual]
}

# how many settings bundle are currently saved
proc getSavedSettingsStackDepth {} {
   return [llength $::g_SAVE_g_loadedModules]
}

# manage settings to save as a stack to have a separate set of settings
# for each module loaded or unloaded in order to be able to restore the
# correct set in case of failure
proc pushSettings {} {
   foreach var {env g_clearedEnvVars g_Aliases g_stateEnvVars g_stateAliases\
      g_stateFunctions g_Functions g_newXResources g_delXResources\
      g_loadedModules g_loadedModuleFiles g_loadedModuleUasked\
      g_loadedModuleConflict g_loadedModulePrereq g_loadedModuleAltname\
      g_moduleDepend g_dependHash g_moduleNPODepend g_dependNPOHash\
      g_prereqViolation g_prereqNPOViolation g_conflictViolation\
      g_moduleUnmetDep g_unmetDepHash g_moduleEval} {
      eval "lappend ::g_SAVE_$var \[array get ::$var\]"
   }
   # save non-array variable and indication if it was set
   foreach var {g_changeDir g_stdoutPuts g_return_text} {
      if {[info exists ::$var]} {
         eval "lappend ::g_SAVE_$var \[list 1 \[set ::$var\]\]"
      } else {
         eval "lappend ::g_SAVE_$var \[list 0 {}\]"
      }
   }
   reportDebug "settings saved (#[getSavedSettingsStackDepth])"
}

proc popSettings {} {
   set flushedid [getSavedSettingsStackDepth]
   foreach var {env g_clearedEnvVars g_Aliases g_stateEnvVars g_stateAliases\
      g_stateFunctions g_Functions g_newXResources g_delXResources\
      g_changeDir g_stdoutPuts g_return_text\
      g_loadedModules g_loadedModuleFiles g_loadedModuleUasked\
      g_loadedModuleConflict g_loadedModulePrereq g_loadedModuleAltname\
      g_moduleDepend g_dependHash g_moduleNPODepend g_dependNPOHash\
      g_prereqViolation g_prereqNPOViolation g_conflictViolation\
      g_moduleUnmetDep g_unmetDepHash g_moduleEval} {
      eval "set ::g_SAVE_$var \[lrange \$::g_SAVE_$var 0 end-1\]"
   }
   reportDebug "previously saved settings flushed (#$flushedid)"
}

proc restoreSettings {} {
   foreach var {env g_clearedEnvVars g_Aliases g_stateEnvVars g_stateAliases\
      g_stateFunctions g_Functions g_newXResources g_delXResources\
      g_loadedModules g_loadedModuleFiles g_loadedModuleUasked\
      g_loadedModuleConflict g_loadedModulePrereq g_loadedModuleAltname\
      g_moduleDepend g_dependHash g_moduleNPODepend g_dependNPOHash\
      g_prereqViolation g_prereqNPOViolation g_conflictViolation\
      g_moduleUnmetDep g_unmetDepHash g_moduleEval} {
      # clear current $var arrays
      if {[info exists ::$var]} {
         eval "unset ::$var; array set ::$var {}"
      }
      eval "array set ::$var \[lindex \$::g_SAVE_$var end\]"
   }
   # restore non-array variable if it was set
   foreach var {g_changeDir g_stdoutPuts g_return_text} {
      if {[info exists ::$var]} {
         eval "unset ::$var"
      }
      eval "lassign \[lindex \$::g_SAVE_$var end\] isdefined val"
      if {$isdefined} {
         set ::$var $val
      }
   }
   reportDebug "previously saved settings restored\
      (#[getSavedSettingsStackDepth])"
}

proc renderSettings {} {
   global g_stateEnvVars g_stateAliases g_stateFunctions g_newXResources\
      g_delXResources

   reportDebug called.

   # required to work on cygwin, shouldn't hurt real linux
   fconfigure stdout -translation lf

   # preliminaries if there is stuff to render
   if {$::g_autoInit || [array size g_stateEnvVars] > 0 ||\
      [array size g_stateAliases] > 0 || [array size g_newXResources] > 0 ||\
      [array size g_stateFunctions] > 0 || [array size g_delXResources] > 0\
      || [info exists ::g_changeDir] || [info exists ::g_stdoutPuts] ||\
      [info exists ::g_return_text]} {
      switch -- $::g_shellType {
         python {
            puts stdout {import os}
         }
      }
      set has_rendered 1
   } else {
      set has_rendered 0
   }

   if {$::g_autoInit} {
      renderAutoinit
   }

   # new environment variables
   foreach var [array names g_stateEnvVars] {
      switch -- $g_stateEnvVars($var) {
         new {
            switch -- $::g_shellType {
               csh {
                  set val [charEscaped $::env($var)]
                  # csh barfs on long env vars
                  if {$::g_shell eq {csh} && [string length $val] >\
                     $::CSH_LIMIT} {
                     if {$var eq {PATH}} {
                        reportWarning "PATH exceeds $::CSH_LIMIT characters,\
                           truncating and appending /usr/bin:/bin ..."
                        set val [string range $val 0 [expr {$::CSH_LIMIT\
                           - 1}]]:/usr/bin:/bin
                     } else {
                         reportWarning "$var exceeds $::CSH_LIMIT characters,\
                            truncating..."
                         set val [string range $val 0 [expr {$::CSH_LIMIT\
                            - 1}]]
                     }
                  }
                  puts stdout "setenv $var $val;"
               }
               sh {
                  puts stdout "$var=[charEscaped $::env($var)];\
                     export $var;"
               }
               fish {
                  set val [charEscaped $::env($var)]
                  # fish shell has special treatment for PATH variable
                  # so its value should be provided as a list separated
                  # by spaces not by semi-colons
                  if {$var eq {PATH}} {
                     regsub -all : $val { } val
                  }
                  puts stdout "set -xg $var $val;"
               }
               tcl {
                  set val $::env($var)
                  puts stdout "set ::env($var) {$val};"
               }
               cmd {
                  set val $::env($var)
                  puts stdout "set $var=$val"
               }
               perl {
                  set val [charEscaped $::env($var) \']
                  puts stdout "\$ENV{'$var'} = '$val';"
               }
               python {
                  set val [charEscaped $::env($var) \']
                  puts stdout "os.environ\['$var'\] = '$val'"
               }
               ruby {
                  set val [charEscaped $::env($var) \']
                  puts stdout "ENV\['$var'\] = '$val'"
               }
               lisp {
                  set val [charEscaped $::env($var) \"]
                  puts stdout "(setenv \"$var\" \"$val\")"
               }
               cmake {
                  set val [charEscaped $::env($var) \"]
                  puts stdout "set(ENV{$var} \"$val\")"
               }
               r {
                  set val [charEscaped $::env($var) {\\'}]
                  puts stdout "Sys.setenv('$var'='$val')"
               }
            }
         }
         del {
            switch -- $::g_shellType {
               csh {
                  puts stdout "unsetenv $var;"
               }
               sh {
                  puts stdout "unset $var;"
               }
               fish {
                  puts stdout "set -e $var;"
               }
               tcl {
                  puts stdout "catch {unset ::env($var)};"
               }
               cmd {
                  puts stdout "set $var="
               }
               perl {
                  puts stdout "delete \$ENV{'$var'};"
               }
               python {
                  puts stdout "os.environ\['$var'\] = ''"
                  puts stdout "del os.environ\['$var'\]"
               }
               ruby {
                  puts stdout "ENV\['$var'\] = nil"
               }
               lisp {
                  puts stdout "(setenv \"$var\" nil)"
               }
               cmake {
                  puts stdout "unset(ENV{$var})"
               }
               r {
                  puts stdout "Sys.unsetenv('$var')"
               }
            }
         }
      }
   }

   foreach var [array names g_stateAliases] {
      switch -- $g_stateAliases($var) {
         new {
            set val $::g_Aliases($var)
            # convert $n in !!:n and $* in !* on csh (like on compat version)
            if {$::g_shellType eq {csh}} {
               regsub -all {([^\\]|^)\$([0-9]+)} $val {\1!!:\2} val
               regsub -all {([^\\]|^)\$\*} $val {\1!*} val
            }
            # unescape \$ after now csh-specific conversion is over
            regsub -all {\\\$} $val {$} val
            switch -- $::g_shellType {
               csh {
                  set val [charEscaped $val]
                  puts stdout "alias $var $val;"
               }
               sh {
                  set val [charEscaped $val]
                  puts stdout "alias $var=$val;"
               }
               fish {
                  set val [charEscaped $val]
                  puts stdout "alias $var $val;"
               }
               cmd {
                  puts stdout "doskey $var=$val"
               }
            }
         }
         del {
            switch -- $::g_shellType {
               csh {
                  puts stdout "unalias $var;"
               }
               sh {
                  puts stdout "unalias $var;"
               }
               fish {
                  puts stdout "functions -e $var;"
               }
               cmd {
                  puts stdout "doskey $var="
               }
            }
         }
      }
   }
   foreach funcname [array names g_stateFunctions] {
      switch -- $g_stateFunctions($funcname) {
         new {
            # trim function body to smoothly add a finishing ;
            set val [string trim $::g_Functions($funcname) "; \t\n\r"]
            switch -- $::g_shellType {
               sh {
                  puts stdout "$funcname () { $val; }; export $funcname;"
               }
               fish {
                  puts stdout "function $funcname; $val; end;"
               }
            }
         }
         del {
            switch -- $::g_shellType {
               sh {
                  puts stdout "unset -f $funcname;"
               }
               fish {
                  puts stdout "functions -e $funcname;"
               }
            }
         }
      }
   }

   # preliminaries for x-resources stuff
   if {[array size g_newXResources] > 0 || [array size g_delXResources] > 0} {
      switch -- $::g_shellType {
         python {
            puts stdout {import subprocess}
         }
         ruby {
            puts stdout {require 'open3'}
         }
      }
   }

   # new x resources
   if {[array size g_newXResources] > 0} {
      # xrdb executable has already be verified in x-resource
      set xrdb [getCommandPath xrdb]
      foreach var [array names g_newXResources] {
         set val $g_newXResources($var)
         # empty val means that var is a file to parse
         if {$val eq {}} {
            switch -- $::g_shellType {
               sh - csh - fish {
                  puts stdout "$xrdb -merge $var;"
               }
               tcl {
                  puts stdout "exec $xrdb -merge $var;"
               }
               perl {
                  puts stdout "system(\"$xrdb -merge $var\");"
               }
               python {
                  set var [charEscaped $var \']
                  puts stdout "subprocess.Popen(\['$xrdb',\
                     '-merge', '$var'\])"
               }
               ruby {
                  set var [charEscaped $var \']
                  puts stdout "Open3.popen2('$xrdb -merge $var')"
               }
               lisp {
                  puts stdout "(shell-command-to-string \"$xrdb\
                     -merge $var\")"
               }
               cmake {
                  puts stdout "execute_process(COMMAND $xrdb -merge $var)"
               }
               r {
                  set var [charEscaped $var {\\'}]
                  puts stdout "system('$xrdb -merge $var')"
               }
            }
         } else {
            switch -- $::g_shellType {
               sh - csh - fish {
                  set var [charEscaped $var \"]
                  set val [charEscaped $val \"]
                  puts stdout "echo \"$var: $val\" | $xrdb -merge;"
               }
               tcl {
                  puts stdout "set XRDBPIPE \[open \"|$xrdb -merge\" r+\];"
                  set var [charEscaped $var \"]
                  set val [charEscaped $val \"]
                  puts stdout "puts \$XRDBPIPE \"$var: $val\";"
                  puts stdout {close $XRDBPIPE;}
                  puts stdout {unset XRDBPIPE;}
               }
               perl {
                  puts stdout "open(XRDBPIPE, \"|$xrdb -merge\");"
                  set var [charEscaped $var \"]
                  set val [charEscaped $val \"]
                  puts stdout "print XRDBPIPE \"$var: $val\\n\";"
                  puts stdout {close XRDBPIPE;}
               }
               python {
                  set var [charEscaped $var \']
                  set val [charEscaped $val \']
                  puts stdout "subprocess.Popen(\['$xrdb', '-merge'\],\
                     stdin=subprocess.PIPE).communicate(input='$var:\
                     $val\\n')"
               }
               ruby {
                  set var [charEscaped $var \']
                  set val [charEscaped $val \']
                  puts stdout "Open3.popen2('$xrdb -merge') {|i,o,t| i.puts\
                     '$var: $val'}"
               }
               lisp {
                  puts stdout "(shell-command-to-string \"echo $var:\
                     $val | $xrdb -merge\")"
               }
               cmake {
                  set var [charEscaped $var \"]
                  set val [charEscaped $val \"]
                  puts stdout "execute_process(COMMAND echo \"$var: $val\"\
                     COMMAND $xrdb -merge)"
               }
               r {
                  set var [charEscaped $var {\\'}]
                  set val [charEscaped $val {\\'}]
                  puts stdout "system('$xrdb -merge', input='$var: $val')"
               }
            }
         }
      }
   }

   if {[array size g_delXResources] > 0} {
      set xrdb [getCommandPath xrdb]
      set xres_to_del {}
      foreach var [array names g_delXResources] {
         # empty val means that var is a file to parse
         if {$g_delXResources($var) eq {}} {
            # xresource file has to be parsed to find what resources
            # are declared there and need to be unset
            foreach fline [split [exec $xrdb -n load $var] \n] {
               lappend xres_to_del [lindex [split $fline :] 0]
            }
         } else {
            lappend xres_to_del $var
         }
      }

      # xresource strings are unset by emptying their value since there
      # is no command of xrdb that can properly remove one property
      switch -- $::g_shellType {
         sh - csh - fish {
            foreach var $xres_to_del {
               puts stdout "echo \"$var:\" | $xrdb -merge;"
            }
         }
         tcl {
            foreach var $xres_to_del {
               puts stdout "set XRDBPIPE \[open \"|$xrdb -merge\" r+\];"
               set var [charEscaped $var \"]
               puts stdout "puts \$XRDBPIPE \"$var:\";"
               puts stdout {close $XRDBPIPE;}
               puts stdout {unset XRDBPIPE;}
            }
         }
         perl {
            foreach var $xres_to_del {
               puts stdout "open(XRDBPIPE, \"|$xrdb -merge\");"
               set var [charEscaped $var \"]
               puts stdout "print XRDBPIPE \"$var:\\n\";"
               puts stdout {close XRDBPIPE;}
            }
         }
         python {
            foreach var $xres_to_del {
               set var [charEscaped $var \']
               puts stdout "subprocess.Popen(\['$xrdb', '-merge'\],\
                  stdin=subprocess.PIPE).communicate(input='$var:\\n')"
            }
         }
         ruby {
            foreach var $xres_to_del {
               set var [charEscaped $var \']
               puts stdout "Open3.popen2('$xrdb -merge') {|i,o,t| i.puts\
                  '$var:'}"
            }
         }
         lisp {
            foreach var $xres_to_del {
               puts stdout "(shell-command-to-string \"echo $var: |\
                  $xrdb -merge\")"
            }
         }
         cmake {
            foreach var $xres_to_del {
               set var [charEscaped $var \"]
               puts stdout "execute_process(COMMAND echo \"$var:\"\
                  COMMAND $xrdb -merge)"
            }
         }
         r {
            foreach var $xres_to_del {
               set var [charEscaped $var {\\'}]
               puts stdout "system('$xrdb -merge', input='$var:')"
            }
         }
      }
   }

   if {[info exists ::g_changeDir]} {
      switch -- $::g_shellType {
         sh - csh - fish {
            puts stdout "cd '$::g_changeDir';"
         }
         tcl {
            puts stdout "cd \"$::g_changeDir\";"
         }
         cmd {
            puts stdout "cd $::g_changeDir"
         }
         perl {
            puts stdout "chdir '$::g_changeDir';"
         }
         python {
            puts stdout "os.chdir('$::g_changeDir')"
         }
         ruby {
            puts stdout "Dir.chdir('$::g_changeDir')"
         }
         lisp {
            puts stdout "(shell-command-to-string \"cd '$::g_changeDir'\")"
         }
         r {
            puts stdout "setwd('$::g_changeDir')"
         }
      }
      # cannot change current directory of cmake "shell"
   }

   # send content deferred during modulefile interpretation
   if {[info exists ::g_stdoutPuts]} {
      foreach putsArgs $::g_stdoutPuts {
         eval puts $putsArgs
         # check if a finishing newline will be needed after content sent
         set needPutsNl [expr {[lindex $putsArgs 0] eq {-nonewline} ? 1 : 0}]
      }
      if {$needPutsNl} {
         puts stdout {}
      }
   }

   # return text value if defined even if error happened
   if {[info exists ::g_return_text]} {
      reportDebug {text value should be returned.}
      renderText $::g_return_text
   } elseif {$::error_count > 0} {
      reportDebug "$::error_count error(s) detected."
      renderFalse
   } elseif {$::g_return_false} {
      reportDebug {false value should be returned.}
      renderFalse
   } elseif {$has_rendered} {
      # finish with true statement if something has been put
      renderTrue
   }
}

proc renderAutoinit {} {
   reportDebug called.

   # automatically detect which tclsh should be used for
   # future module commands
   set tclshbin [info nameofexecutable]

   # ensure script path is absolute
   set ::argv0 [getAbsolutePath $::argv0]

   switch -- $::g_shellType {
      csh {
         set pre_hi {set _histchars = $histchars; unset histchars;}
         set post_hi {set histchars = $_histchars; unset _histchars;}
         set pre_pr {set _prompt=$prompt:q; set prompt="";}
         set post_pr {set prompt=$_prompt:q; unset _prompt;}
         set eval_cmd "eval \"`$tclshbin $::argv0 $::g_shell \\!*:q`\";"
         set pre_ex {set _exit="$status";}
         set post_ex {test 0 = $_exit}

         set fdef "if ( \$?histchars && \$?prompt )\
alias module '$pre_hi $pre_pr $eval_cmd $pre_ex $post_hi $post_pr $post_ex' ;
if ( \$?histchars && ! \$?prompt )\
alias module '$pre_hi $eval_cmd $pre_ex $post_hi $post_ex' ;
if ( ! \$?histchars && \$?prompt )\
alias module '$pre_pr $eval_cmd $pre_ex $post_pr $post_ex' ;
if ( ! \$?histchars && ! \$?prompt ) alias module '$eval_cmd' ;"
      }
      sh {
         # Considering the diversity of ways local variables are handled
         # through the sh-variants ('local' known everywhere except on ksh,
         # 'typeset' known everywhere except on pure-sh, and on some systems
         # the pure-sh is in fact a 'ksh'), no local variables are defined and
         # these variables that should have been local are unset at the end

         # on zsh, word splitting should be enabled explicitly
         set wsplit [expr {$::g_shell eq {zsh} ? {=} : {}}]
         # only redirect module from stderr to stdout when session is
         # attached to a terminal to avoid breaking non-terminal session
         # (scp, sftp, etc)
         set fname [expr {[isStderrTty] ? {_module_raw} : {module}}]
         # build quarantine mechanism in module function
         # an empty runtime variable is set even if no corresponding
         # MODULES_RUNENV_* variable found, as var cannot be unset on
         # modified environment command-line
         set fdef "${fname}() {"
@silentshdbgsupport@         append fdef {
@silentshdbgsupport@   unset _mlshdbg;
@silentshdbgsupport@   if [ "${MODULES_SILENT_SHELL_DEBUG:-0}" = '1' ]; then
@silentshdbgsupport@      case "$-" in
@silentshdbgsupport@         *v*x*) set +vx; _mlshdbg='vx' ;;
@silentshdbgsupport@         *v*) set +v; _mlshdbg='v' ;;
@silentshdbgsupport@         *x*) set +x; _mlshdbg='x' ;;
@silentshdbgsupport@         *) _mlshdbg='' ;;
@silentshdbgsupport@      esac;
@silentshdbgsupport@   fi;}
@quarantinesupport@         append fdef "
@quarantinesupport@   unset _mlre _mlIFS;
@quarantinesupport@   if \[ -n \"\${IFS+x}\" \]; then
@quarantinesupport@      _mlIFS=\$IFS;
@quarantinesupport@   fi;
@quarantinesupport@   IFS=' ';
@quarantinesupport@   for _mlv in \${${wsplit}MODULES_RUN_QUARANTINE:-}; do"
@quarantinesupport@         append fdef {
@quarantinesupport@      if [ "${_mlv}" = "${_mlv##*[!A-Za-z0-9_]}" -a "${_mlv}" = "${_mlv#[0-9]}" ]; then
@quarantinesupport@         if [ -n "`eval 'echo ${'$_mlv'+x}'`" ]; then
@quarantinesupport@            _mlre="${_mlre:-}${_mlv}_modquar='`eval 'echo ${'$_mlv'}'`' ";
@quarantinesupport@         fi;
@quarantinesupport@         _mlrv="MODULES_RUNENV_${_mlv}";
@quarantinesupport@         _mlre="${_mlre:-}${_mlv}='`eval 'echo ${'$_mlrv':-}'`' ";
@quarantinesupport@      fi;
@quarantinesupport@   done;
@quarantinesupport@   if [ -n "${_mlre:-}" ]; then}
@quarantinesupport@         append fdef "\n      eval `eval \${${wsplit}_mlre}$tclshbin $::argv0\
@quarantinesupport@$::g_shell '\"\$@\"'`;
@quarantinesupport@   else
@quarantinesupport@      eval `$tclshbin $::argv0 $::g_shell \"\$@\"`;
@quarantinesupport@   fi;"
@notquarantinesupport@         append fdef "
@notquarantinesupport@   eval `$tclshbin $::argv0 $::g_shell \"\$@\"`;"
         append fdef {
   _mlstatus=$?;}
@quarantinesupport@         append fdef {
@quarantinesupport@   if [ -n "${_mlIFS+x}" ]; then
@quarantinesupport@      IFS=$_mlIFS;
@quarantinesupport@   else
@quarantinesupport@      unset IFS;
@quarantinesupport@   fi;
@quarantinesupport@   unset _mlre _mlv _mlrv _mlIFS;}
@silentshdbgsupport@         append fdef {
@silentshdbgsupport@   if [ -n "${_mlshdbg:-}" ]; then
@silentshdbgsupport@      set -$_mlshdbg;
@silentshdbgsupport@   fi;
@silentshdbgsupport@   unset _mlshdbg;}
         append fdef {
   return $_mlstatus;}
         append fdef "\n};"
         if {[isStderrTty]} {
            append fdef "\nmodule() { _module_raw \"\$@\" 2>&1; };"
         }
      }
      fish {
         set fdef [expr {[isStderrTty] ? "function _module_raw\n" :\
            "function module\n"}]
@quarantinesupport@         append fdef {   set -l _mlre ''; set -l _mlv; set -l _mlrv;
@quarantinesupport@   for _mlv in (string split ' ' $MODULES_RUN_QUARANTINE)
@quarantinesupport@      if string match -r '^[A-Za-z_][A-Za-z0-9_]*$' $_mlv >/dev/null
@quarantinesupport@         if set -q $_mlv
@quarantinesupport@            set _mlre $_mlre$_mlv"_modquar='$$_mlv' "
@quarantinesupport@         end
@quarantinesupport@         set _mlrv "MODULES_RUNENV_$_mlv"
@quarantinesupport@         set _mlre "$_mlre$_mlv='$$_mlrv' "
@quarantinesupport@      end
@quarantinesupport@   end
@quarantinesupport@   if [ -n "$_mlre" ]
@quarantinesupport@      set _mlre "env $_mlre"
@quarantinesupport@   end}
         # use "| source -" rather than "eval" to be able
         # to redirect stderr after stdout being evaluated
@quarantinesupport@         append fdef "\n   eval \$_mlre $tclshbin $::argv0 $::g_shell\
            (string escape -- \$argv) | source -\n"
@notquarantinesupport@         append fdef "   eval $tclshbin $::argv0 $::g_shell\
            (string escape -- \$argv) | source -\n"
         if {[isStderrTty]} {
            append fdef {end
function module
   _module_raw $argv ^&1
end}
         } else {
            append fdef end
         }
      }
      tcl {
         set fdef "proc module {args} {"
@quarantinesupport@         append fdef {
@quarantinesupport@   set _mlre {};
@quarantinesupport@   if {[info exists ::env(MODULES_RUN_QUARANTINE)]} {
@quarantinesupport@      foreach _mlv [split $::env(MODULES_RUN_QUARANTINE) " "] {
@quarantinesupport@         if {[regexp {^[A-Za-z_][A-Za-z0-9_]*$} $_mlv]} {
@quarantinesupport@            if {[info exists ::env($_mlv)]} {
@quarantinesupport@               lappend _mlre "${_mlv}_modquar=$::env($_mlv)"
@quarantinesupport@            }
@quarantinesupport@            set _mlrv "MODULES_RUNENV_${_mlv}"
@quarantinesupport@            lappend _mlre [expr {[info exists ::env($_mlrv)] ?\
               "${_mlv}=$::env($_mlrv)" : "${_mlv}="}]
@quarantinesupport@         }
@quarantinesupport@      }
@quarantinesupport@      if {[llength $_mlre] > 0} {
@quarantinesupport@         set _mlre [linsert $_mlre 0 "env"]
@quarantinesupport@      }
@quarantinesupport@   }}
      append fdef {
   set _mlstatus 1;}
@quarantinesupport@         append fdef "\n   catch {eval exec \$_mlre \"$tclshbin\"\
            \"$::argv0\" \"$::g_shell\" \$args 2>@stderr} script\n"
@notquarantinesupport@         append fdef "\n   catch {eval exec \"$tclshbin\"\
            \"$::argv0\" \"$::g_shell\" \$args 2>@stderr} script\n"
         append fdef {   eval $script;
   return $_mlstatus}
         append fdef "\n}"
      }
      cmd {
         reportErrorAndExit {No autoinit mode available for 'cmd' shell}
      }
      perl {
         set fdef "sub module {"
@quarantinesupport@         append fdef {
@quarantinesupport@   my $_mlre = '';
@quarantinesupport@   if (defined $ENV{'MODULES_RUN_QUARANTINE'}) {
@quarantinesupport@      foreach my $_mlv (split(' ', $ENV{'MODULES_RUN_QUARANTINE'})) {
@quarantinesupport@         if ($_mlv =~ /^[A-Za-z_][A-Za-z0-9_]*$/) {
@quarantinesupport@            if (defined $ENV{$_mlv}) {
@quarantinesupport@               $_mlre .= "${_mlv}_modquar='$ENV{$_mlv}' ";
@quarantinesupport@            }
@quarantinesupport@            my $_mlrv = "MODULES_RUNENV_$_mlv";
@quarantinesupport@            $_mlre .= "$_mlv='$ENV{$_mlrv}' ";
@quarantinesupport@        }
@quarantinesupport@      }
@quarantinesupport@      if ($_mlre ne "") {
@quarantinesupport@         $_mlre = "env $_mlre";
@quarantinesupport@      }
@quarantinesupport@   }}
         append fdef {
   my $args = '';
   if (@_ > 0) {
      $args = '"' . join('" "', @_) . '"';
   }
   my $_mlstatus = 1;}
@quarantinesupport@         append fdef "\n   eval `\${_mlre}$tclshbin $::argv0 perl \$args`;\n"
@notquarantinesupport@         append fdef "\n   eval `$tclshbin $::argv0 perl \$args`;\n"
         append fdef {   return $_mlstatus;}
         append fdef "\n}"
      }
      python {
         set fdef {import re, subprocess
def module(*arguments):}
@quarantinesupport@         append fdef {
@quarantinesupport@   _mlre = os.environ.copy()
@quarantinesupport@   if 'MODULES_RUN_QUARANTINE' in os.environ:
@quarantinesupport@      for _mlv in os.environ['MODULES_RUN_QUARANTINE'].split():
@quarantinesupport@         if re.match('^[A-Za-z_][A-Za-z0-9_]*$', _mlv):
@quarantinesupport@            if _mlv in os.environ:
@quarantinesupport@               _mlre[_mlv + '_modquar'] = os.environ[_mlv]
@quarantinesupport@            _mlrv = 'MODULES_RUNENV_' + _mlv
@quarantinesupport@            if _mlrv in os.environ:
@quarantinesupport@               _mlre[_mlv] = os.environ[_mlrv]
@quarantinesupport@            else:
@quarantinesupport@               _mlre[_mlv] = ''}
         append fdef {
   ns = {}}
@quarantinesupport@         append fdef "\n   exec(subprocess.Popen(\['$tclshbin',\
            '$::argv0', 'python'\] + list(arguments),\
            stdout=subprocess.PIPE, env=_mlre).communicate()\[0\], ns)\n"
@notquarantinesupport@         append fdef "\n   exec(subprocess.Popen(\['$tclshbin',\
            '$::argv0', 'python'\] + list(arguments),\
            stdout=subprocess.PIPE).communicate()\[0\], ns)\n"
         append fdef {   if '_mlstatus' in ns:
      _mlstatus = ns['_mlstatus']
   else:
      _mlstatus = True
   return _mlstatus}
      }
      ruby {
         set fdef {class ENVModule
   def ENVModule.module(*args)}
@quarantinesupport@         append fdef {
@quarantinesupport@      _mlre = ''
@quarantinesupport@      if ENV.has_key?('MODULES_RUN_QUARANTINE') then
@quarantinesupport@         ENV['MODULES_RUN_QUARANTINE'].split(' ').each do |_mlv|
@quarantinesupport@            if _mlv =~ /^[A-Za-z_][A-Za-z0-9_]*$/ then
@quarantinesupport@               if ENV.has_key?(_mlv) then
@quarantinesupport@                  _mlre << _mlv + "_modquar='" + ENV[_mlv].to_s + "' "
@quarantinesupport@               end
@quarantinesupport@               _mlrv = 'MODULES_RUNENV_' + _mlv
@quarantinesupport@               _mlre << _mlv + "='" + ENV[_mlrv].to_s + "' "
@quarantinesupport@            end
@quarantinesupport@         end
@quarantinesupport@         unless _mlre.empty?
@quarantinesupport@            _mlre = 'env ' + _mlre
@quarantinesupport@         end
@quarantinesupport@      end}
         append fdef {
      if args[0].kind_of?(Array) then
         args = args[0]
      end
      if args.length == 0 then
         args = ''
      else
         args = "\"#{args.join('" "')}\""
      end
      _mlstatus = true}
@quarantinesupport@         append fdef "\n      eval `#{_mlre}$tclshbin $::argv0 ruby #{args}`\n"
@notquarantinesupport@         append fdef "\n      eval `$tclshbin $::argv0 ruby #{args}`\n"
         append fdef {      return _mlstatus
   end
end}
      }
      lisp {
         reportErrorAndExit {lisp mode autoinit not yet implemented}
      }
      cmake {
@quarantinesupport@         set pre_exec "\n      execute_process(COMMAND \${_mlre} $tclshbin\
            $::argv0 cmake "
@notquarantinesupport@         set pre_exec "\n      execute_process(COMMAND $tclshbin\
            $::argv0 cmake "
         set post_exec "\n         OUTPUT_FILE \${tempfile_name})\n"
         set fdef {function(module)
   cmake_policy(SET CMP0007 NEW)}
@quarantinesupport@         append fdef {
@quarantinesupport@   set(_mlre "")
@quarantinesupport@   if(DEFINED ENV{MODULES_RUN_QUARANTINE})
@quarantinesupport@      string(REPLACE " " ";" _mlv_list "$ENV{MODULES_RUN_QUARANTINE}")
@quarantinesupport@      foreach(_mlv ${_mlv_list})
@quarantinesupport@         if(${_mlv} MATCHES "^[A-Za-z_][A-Za-z0-9_]*$")
@quarantinesupport@            if(DEFINED ENV{${_mlv}})
@quarantinesupport@               set(_mlre "${_mlre}${_mlv}_modquar=$ENV{${_mlv}};")
@quarantinesupport@            endif()
@quarantinesupport@            set(_mlrv "MODULES_RUNENV_${_mlv}")
@quarantinesupport@            set(_mlre "${_mlre}${_mlv}=$ENV{${_mlrv}};")
@quarantinesupport@        endif()
@quarantinesupport@      endforeach()
@quarantinesupport@      if (NOT "${_mlre}" STREQUAL "")
@quarantinesupport@         set(_mlre "env;${_mlre}")
@quarantinesupport@      endif()
@quarantinesupport@   endif()}
         append fdef {
   set(_mlstatus TRUE)
   execute_process(COMMAND mktemp -t moduleinit.cmake.XXXXXXXXXXXX
      OUTPUT_VARIABLE tempfile_name
      OUTPUT_STRIP_TRAILING_WHITESPACE)
   if(${ARGC} EQUAL 1)}
            # adapt command definition depending on the number of args to be
            # able to pass to some extend (<5 args) empty string element to
            # modulecmd (no other way as empty element in ${ARGV} are skipped
            append fdef "$pre_exec\"\${ARGV0}\"$post_exec"
            append fdef {   elseif(${ARGC} EQUAL 2)}
            append fdef "$pre_exec\"\${ARGV0}\" \"\${ARGV1}\"$post_exec"
            append fdef {   elseif(${ARGC} EQUAL 3)}
            append fdef "$pre_exec\"\${ARGV0}\" \"\${ARGV1}\"\
               \"\${ARGV2}\"$post_exec"
            append fdef {   elseif(${ARGC} EQUAL 4)}
            append fdef "$pre_exec\"\${ARGV0}\" \"\${ARGV1}\"\
               \"\${ARGV2}\" \"\${ARGV3}\"$post_exec"
            append fdef {   else()}
            append fdef "$pre_exec\${ARGV}$post_exec"
            append fdef {   endif()
   if(EXISTS ${tempfile_name})
      include(${tempfile_name})
      file(REMOVE ${tempfile_name})
   endif()
   set(module_result ${_mlstatus} PARENT_SCOPE)
endfunction(module)}
      }
      r {
         set fdef "module <- function(...){"
@quarantinesupport@         append fdef {
@quarantinesupport@   mlre <- ''
@quarantinesupport@   if (!is.na(Sys.getenv('MODULES_RUN_QUARANTINE', unset=NA))) {
@quarantinesupport@      for (mlv in strsplit(Sys.getenv('MODULES_RUN_QUARANTINE'), ' ')[[1]]) {
@quarantinesupport@         if (grepl('^[A-Za-z_][A-Za-z0-9_]*$', mlv)) {
@quarantinesupport@            if (!is.na(Sys.getenv(mlv, unset=NA))) {
@quarantinesupport@               mlre <- paste0(mlre, mlv, "_modquar='", Sys.getenv(mlv), "' ")
@quarantinesupport@            }
@quarantinesupport@            mlrv <- paste0('MODULES_RUNENV_', mlv)
@quarantinesupport@            mlre <- paste0(mlre, mlv, "='", Sys.getenv(mlrv), "' ")
@quarantinesupport@         }
@quarantinesupport@      }
@quarantinesupport@      if (mlre != '') {
@quarantinesupport@         mlre <- paste0('env ', mlre)
@quarantinesupport@      }
@quarantinesupport@   }}
         append fdef {
   arglist <- as.list(match.call())
   arglist[1] <- 'r'
   args <- paste0('"', paste0(arglist, collapse='" "'), '"')}
@quarantinesupport@         append fdef "\n   cmd <- paste(mlre, '$tclshbin', '$::argv0', args,\
            sep=' ')\n"
@notquarantinesupport@         append fdef "\n   cmd <- paste('$tclshbin', '$::argv0', args,\
            sep=' ')\n"
         append fdef {   mlstatus <- TRUE
   hndl <- pipe(cmd)
   eval(expr = parse(file=hndl))
   close(hndl)
   invisible(mlstatus)}
         append fdef "\n}"

      }
   }

   # output function definition
   puts stdout $fdef
}

proc cacheCurrentModules {} {
   # parse loaded modules information only once, global arrays are updated
   # afterwards when module commands update loaded modules state
   if {![info exists ::g_lm_info_cached]} {
      set ::g_lm_info_cached 1
      # mark specific as well as generic modules as loaded
      set i 0
      set modfilelist [getLoadedModuleFileList]
      set modlist [getLoadedModuleList]
      set nuaskedlist [getLoadedModuleNotUserAskedList]

      if {[llength $modlist] == [llength $modfilelist]} {
         # cache declared alternative names of loaded modules
         foreach modalt [getLoadedModuleAltnameList] {
            eval setLoadedAltname $modalt
         }

         # cache declared conflict of loaded modules
         foreach modcon [getLoadedModuleConflictList] {
            eval setLoadedConflict $modcon
         }

         # cache declared prereq of loaded modules, prior to setLoadedModule
         # which triggers dependency chain build
         foreach modpre [getLoadedModulePrereqList] {
            eval setLoadedPrereq $modpre
         }

         foreach mod $modlist {
            setLoadedModule $mod [lindex $modfilelist $i] [notInList\
               $nuaskedlist $mod]
            incr i
         }

         reportDebug "$i loaded"
      } else {
         reportErrorAndExit "Loaded environment state is inconsistent\n \
            LOADEDMODULES=$modlist\n  _LMFILES_=$modfilelist"
      }
   }
}

# This proc resolves module aliases or version aliases to the real module name
# and version.
proc resolveModuleVersionOrAlias {name} {
   set ret [expr {[info exists ::g_moduleResolved($name)] ?\
      $::g_moduleResolved($name) : $name}]

   reportDebug "'$name' resolved to '$ret'"
   return $ret
}

proc charEscaped {str {charlist { \\\t\{\}|<>!;#^$&*?"'`()}}} {
   return [regsub -all "\(\[$charlist\]\)" $str {\\\1}]
}

proc charUnescaped {str {charlist { \\\t\{\}|<>!;#^$&*?"'`()}}} {
   return [regsub -all "\\\\\(\[$charlist\]\)" $str {\1}]
}

# find command path and remember it
proc getCommandPath {cmd} {
   return [lindex [auto_execok $cmd] 0]
}

# find then run command or raise error if command not found
proc runCommand {cmd args} {
   set cmdpath [getCommandPath $cmd]
   if {$cmdpath eq {}} {
      error "GLOBALERR Command '$cmd' cannot be found"
   } else {
      return [eval exec $cmdpath $args]
   }
}

proc getAbsolutePath {path} {
   # currently executing a modulefile or rc, so get the directory of this file
   if {$::ModulesCurrentModulefile ne {}} {
      set curdir [file dirname $::ModulesCurrentModulefile]
   # elsewhere get module command current working directory
   } else {
      # register pwd at first call
      if {![info exists ::cwd]} {
         set ::cwd [pwd]
      }
      set curdir $::cwd
   }

   # empty result if empty path
   if {$path eq {}} {
      set abspath {}
   } else {
      set abslist {}
      # get a first version of the absolute path by joining the current
      # working directory to the given path. if given path is already absolute
      # 'file join' will not break it as $curdir will be ignored as soon a
      # beginning '/' character is found on $path. this first pass also clean
      # extra '/' character. then each element of the path is analyzed to
      # clear "." and ".." components.
      foreach elt [file split [file join $curdir $path]] {
         if {$elt eq {..}} {
            # skip ".." element if it comes after root element, remove last
            # element elsewhere
            if {[llength $abslist] > 1} {
               set abslist [lreplace $abslist end end]
            }
         # skip any "." element
         } elseif {$elt ne {.}} {
            lappend abslist $elt
         }
      }
      set abspath [eval file join $abslist]
   }

   # return cleaned absolute path
   return $abspath
}

# split string while ignore any separator character that is espaced
proc psplit {str sep} {
   # use standard split if no sep character found
   if {[string first \\$sep $str] == -1} {
      set res [split $str $sep]
   } else {
      set previdx -1
      set idx [string first $sep $str]
      while {$idx != -1} {
         # look ahead if found separator is escaped
         if {[string index $str [expr {$idx-1}]] ne "\\"} {
            # unescape any separator character when adding to list
            lappend res [charUnescaped [string range $str [expr {$previdx+1}]\
               [expr {$idx-1}]] $sep]
            set previdx $idx
         }
         set idx [string first $sep $str [expr {$idx+1}]]
      }

      lappend res [charUnescaped [string range $str [expr {$previdx+1}] end]\
         $sep]
   }

   return $res
}

# join list while escape any character equal to separator
proc pjoin {lst sep} {
   # use standard join if no sep character found
   if {[string first $sep $lst] == -1} {
      set res [join $lst $sep]
   } else {
      set res {}
      foreach elt $lst {
         # preserve empty entries
         if {[info exists not_first]} {
            append res $sep
         } else {
            set not_first 1
         }
         # escape any separator character when adding to string
         append res [charEscaped $elt $sep]
      }
   }

   return $res
}

# Dictionary-style string comparison
# Use dictionary sort of lsort proc to compare two strings in the "string
# compare" fashion (returning -1, 0 or 1). Tcl dictionary-style comparison
# enables to compare software versions (ex: "1.10" is greater than "1.8")
proc compareVersion {str1 str2} {
   if {$str1 eq $str2} {
      return 0
   # put both strings in a list, then lsort it and get first element
   } elseif {[lindex [lsort -dictionary [list $str1 $str2]] 0] eq $str1} {
      return -1
   } else {
      return 1
   }
}

# provide a lreverse proc for Tcl8.4 and earlier
if {[info commands lreverse] eq {}} {
   proc lreverse {l} {
      set r [list]
      for {set i [expr {[llength $l] - 1}]} {$i >= 0} {incr i -1} {
         lappend r [lindex $l $i]
      }
      return $r
   }
}

# provide a lassign proc for Tcl8.4 and earlier
if {[info commands lassign] eq {}} {
   proc lassign {values args} {
      uplevel 1 [list foreach $args [linsert $values end {}] break]
      lrange $values [llength $args] end
   }
}

proc isInList {lst elt} {
   return [expr {[lsearch -exact $lst $elt] != -1}]
}

proc notInList {lst elt} {
   return [expr {[lsearch -exact $lst $elt] == -1}]
}

proc appendNoDupToList {lstname args} {
   set ret 0
   upvar $lstname lst
   foreach elt $args {
      if {![info exists lst] || [notInList $lst $elt]} {
         lappend lst $elt
         set ret 1
      }
   }
   return $ret
}

proc replaceFromList {list1 item {item2 {}}} {
    while {[set xi [lsearch -exact $list1 $item]] >= 0} {
       set list1 [if {[string length $item2] == 0} {lreplace $list1 $xi $xi}\
         {lreplace $list1 $xi $xi $item2}]
    }

    return $list1
}

# returns elements from list1 not part of list2 and elements from list2 not
# part of list1
proc getDiffBetweenList {list1 list2} {
   set res1 [list]
   set res2 [list]

   foreach elt $list1 {
      if {[notInList $list2 $elt]} {
         lappend res1 $elt
      }
   }
   foreach elt $list2 {
      if {[notInList $list1 $elt]} {
         lappend res2 $elt
      }
   }

   return [list $res1 $res2]
}

proc parseAccessIssue {modfile} {
   # retrieve and return access issue message
   if {[regexp {POSIX .* \{(.*)\}$} $::errorCode match errMsg]} {
      return "[string totitle $errMsg] on '$modfile'"
   } else {
      return "Cannot access '$modfile'"
   }
}

proc checkValidModule {modfile} {
   reportDebug $modfile

   # test file only once, cache result obtained to minimize file query
   return [expr {[info exists ::g_modfileValid($modfile)]\
      ? $::g_modfileValid($modfile)\
      : [set ::g_modfileValid($modfile) [readModuleContent $modfile 1 1 1]]}]
}

# get file modification time, cache it at first query, use cache afterward
proc getFileMtime {fpath} {
   if {[info exists ::g_fileMtime($fpath)]} {
      return $::g_fileMtime($fpath)
   } else {
      return [set ::g_fileMtime($fpath) [file mtime $fpath]]
   }
}

# define proc that will be used as fallback to command provided by extension
# library in case this library is not loaded
proc __readFile {filename {firstline 0}} {
   set fid [open $filename r]
   set fdata [if {$firstline} {gets $fid} {read $fid}]
   close $fid
   return $fdata
}

proc readModuleContent {modfile {report_read_issue 0} {must_have_cookie 1}\
   {only_check_validity 0}} {
   reportDebug $modfile
   set res {}

   # read file
   if {[catch {
      if {[info exists ::g_modfileContent($modfile)]} {
         lassign $::g_modfileContent($modfile) fh fdata
      } else {
         # only read beginning of file if just checking validity and not
         # asked to always fully read files
         set fdata [readFile $modfile [expr {$only_check_validity &&\
            ![currentAlwaysReadFullFile]}]]
         # extract magic cookie (first word of modulefile)
         set fh [lindex [split [string range $fdata 0 32]] 0]
         # cache full file read to minimize file operations
         if {!$only_check_validity || [currentAlwaysReadFullFile]} {
            set ::g_modfileContent($modfile) [list $fh $fdata]
         }
      }
   } errMsg ]} {
      if {$report_read_issue} {
         set msg [parseAccessIssue $modfile]
         if {$only_check_validity} {
            set res [list accesserr $msg]
         } else {
            reportError $msg
         }
      }
   } else {
      # check module validity if magic cookie is mandatory
      if {$must_have_cookie && ![string equal -length 8 $fh {#%Module}]} {
         set msg {Magic cookie '#%Module' missing}
         if {$only_check_validity} {
            set res [list invalid $msg]
         } else {
            reportInternalBug $msg $modfile
         }
      # check if min version requirement is met if magic cookie is mandatory
      } elseif {$must_have_cookie && [string length $fh] > 8 &&\
         [compareVersion {@MODULES_RELEASE@} [string range $fh 8 end]] <0} {
         set msg "Modulefile requires at least Modules version [string range\
            $fh 8 end]"
         if {$only_check_validity} {
            set res [list invalid $msg]
         } else {
            reportInternalBug $msg $modfile
         }
      } else {
         if {$only_check_validity} {
            # set validity information as result
            set res [list true {}]
         } else {
            # set file content as result
            set res $fdata
         }
      }
   }

   return $res
}

# If given module maps to default or other symbolic versions, a list of
# those versions is returned. This takes module/version as an argument.
proc getVersAliasList {mod} {
   set tag_list [expr {[info exists ::g_symbolHash($mod)] ?\
      $::g_symbolHash($mod) : {}}]

   reportDebug "'$mod' has tag list '$tag_list'"

   return $tag_list
}

# get list of elements located in a directory passed as argument. a flag is
# set after each element to know if it is considered hidden or not. a
# fetch_hidden argument is there to control search of hidden elements. a
# fetch_dotversion argument controls whether .version file should be looked at
# in directory .proc will be used as a fallback to command provided by
# extension library
proc __getFilesInDirectory {dir fetch_hidden fetch_dotversion} {
   set dir_list [list]

   # try then catch any issue rather than test before trying
   # workaround 'glob -nocomplain' which does not return permission
   # error on Tcl 8.4, so we need to avoid registering issue if
   # raised error is about a no match
   if {[catch {set elt_list [glob $dir/*]} errMsg]} {
      if {$errMsg eq "no files matched glob pattern \"$dir/*\""} {
         set elt_list {}
      } else {
         # rethrow other error to catch it in caller proc
         error $errMsg $::errorInfo $::errorCode
      }
   }

   # Add each element in the current directory to the list
   if {[file readable $dir/.modulerc]} {
      lappend dir_list $dir/.modulerc 0
   }
   if {$fetch_dotversion && [file readable $dir/.version]} {
      lappend dir_list $dir/.version 0
   }
   foreach elt $elt_list {
      lappend dir_list $elt 0
   }

   # search for hidden files if asked
   if {$fetch_hidden} {
      foreach elt [glob -nocomplain -types hidden -directory\
         $dir -tails *] {
         switch -- $elt {
            .modulerc - .version - . - .. { }
            default {
               lappend dir_list $dir/$elt 1
            }
         }
      }
   }

   return $dir_list
}

# check if an existing findModules cache entry matches current search by
# evaluating search ids. if an exact match cannot be found, look at saved
# searches that contains current search (superset of looked elements), extra
# elements will be filtered-out by GetModules
proc findModulesInMemCache {searchid} {
   # exact same search is cached
   if {[info exists ::g_foundModulesMemCache($searchid)]} {
      set match_searchid $searchid
      set mod_list $::g_foundModulesMemCache($searchid)
   # look for a superset search
   } else {
      set match_searchid {}
      set mod_list {}
      foreach cacheid [array names ::g_foundModulesMemCache] {
         # cache id acts as pattern to check if it contains current search
         if {[string match $cacheid $searchid]} {
            set match_searchid $cacheid
            set mod_list $::g_foundModulesMemCache($cacheid)
            break
         }
      }
   }

   return [list $match_searchid $mod_list]
}

# finds all module-related files matching mod in the module path dir
proc findModules {dir mod depthlvl fetch_mtime fetch_hidden} {
   reportDebug "finding '$mod' in $dir (depthlvl=$depthlvl,\
      fetch_mtime=$fetch_mtime, fetch_hidden=$fetch_hidden)"

   # generated search id (for cache search/save) by compacting given args
   set searchid $dir:$mod:$depthlvl:$fetch_mtime:$fetch_hidden

   # look at memory cache for a compatible result
   lassign [findModulesInMemCache $searchid] cache_searchid cache_list
   if {$cache_searchid ne {}} {
      reportDebug "use cache entry '$cache_searchid'"
      return $cache_list
   }

   # skip search in top dir if directly looking to a deep element, which means
   # findModules has already been called and top dir has already been analyzed
   if {[file dirname $mod] eq {.}} {
      # use catch protection to handle non-readable and non-existent dir
      if {[catch {
         set full_list {}
         foreach {fpelt hid} [getFilesInDirectory $dir $fetch_hidden 0] {
            set elt [file tail $fpelt]
            # include any .modulerc file found at the modulepath root
            if {$elt eq {.modulerc} || $mod eq {} || [string match $mod\
               $elt]} {
               lappend full_list $fpelt
            }
         }
      }]} {
         return {}
      }
   } else {
      lappend full_list [file join $dir $mod]
   }

   foreach igndir [getIgnoredDirs] {
      set ignored_dirs($igndir) 1
   }
   array set mod_list {}
   for {set i 0} {$i < [llength $full_list]} {incr i 1} {
      set element [lindex $full_list $i]
      set tag_list {}

      set tail [file tail $element]
      set modulename [getModuleNameFromModulepath $element $dir]
      set parentname [file dirname $modulename]
      set moddepthlvl [llength [file split $modulename]]
      set add_ref_to_parent 0
      if {[file isdirectory $element]} {
         if {![info exists ignored_dirs($tail)]} {
            if {[catch {
               set elt_list [getFilesInDirectory $element $fetch_hidden 1]
            } errMsg]} {
               set mod_list($modulename) [list accesserr [parseAccessIssue\
                  $element] $element]
            } else {
               set mod_list($modulename) [list directory]
               # Add each element in the current directory to the list
               foreach {fpelt hid} $elt_list {
                  lappend full_list $fpelt
                  # Flag hidden files
                  if {$hid} {
                     set hidden_list($fpelt) 1
                  }
               }
               set add_ref_to_parent 1
            }
         }
      } else {
         switch -glob -- $tail {
            .modulerc {
               set mod_list($modulename) [list modulerc]
            }
            .version {
               # skip .version file from different depth level than search
               # targets if no in depth mode is enabled
               if {$depthlvl == 0 || $moddepthlvl == $depthlvl} {
                  set mod_list($modulename) [list modulerc]
               }
            }
            *~ - *,v - \#*\# { }
            default {
               # skip modfile in no in depth mode search if it does not relate
               # to targeted depth level and one valid modfile has already be
               # found for the dirs lying at other depth level
               if {$depthlvl == 0 || $moddepthlvl == $depthlvl || ![info\
                  exists modfile_indir($parentname)]} {
                  lassign [checkValidModule $element] check_valid check_msg
                  switch -- $check_valid {
                     true {
                        set mtime [expr {$fetch_mtime ? [getFileMtime\
                           $element] : {}}]
                        set mod_list($modulename) [list modulefile $mtime]
                        # if modfile hidden, do not ref it in parent list
                        set add_ref_to_parent [expr {$fetch_hidden && [info\
                           exists hidden_list($element)] ? 0 : 1}]

                        # a valid modfile has been found in directory
                        if {$add_ref_to_parent} {
                           set modfile_indir($parentname) 1
                        }
                     }
                     default {
                        # register check error and relative message to get it
                        # in case of direct access of this module element, but
                        # no registering in parent directory structure as
                        # element is not valid
                        set mod_list($modulename) [list $check_valid\
                           $check_msg $element]
                     }
                  }
               }
            }
         }
      }

      # add reference to parent structure
      if {$add_ref_to_parent && [info exists mod_list($parentname)]} {
         lappend mod_list($parentname) $tail
      }
   }

   reportDebug "found [array names mod_list]"

   # cache search results
   reportDebug "create cache entry '$searchid'"
   set found_list [array get mod_list]
   set ::g_foundModulesMemCache($searchid) $found_list

   return $found_list
}

proc getModules {dir {mod {}} {fetch_mtime 0} {search {}} {fetch_hidden 0}} {
   global g_sourceAlias g_sourceVersion g_sourceVirtual g_resolvedPath
   global g_rcAlias g_moduleAlias g_rcVersion g_moduleVersion
   global g_rcVirtual g_moduleVirtual g_rcfilesSourced

   reportDebug "get '$mod' in $dir (fetch_mtime=$fetch_mtime, search=$search,\
      fetch_hidden=$fetch_hidden)"

   # perform an in depth search or not
   set indepth [expr {[isInList $search noindepth] ? 0 : 1}]

   # if search for global or user rc alias only, no dir lookup is performed
   # and aliases from g_rcAlias are returned
   if {[isInList $search rc_alias_only]} {
      set add_rc_defs 1
      array set found_list {}
   } else {
      # find modules by searching with first path element if mod is a deep
      # modulefile (elt1/etl2/vers) in order to catch all .modulerc and
      # .version files of module-related parent directories in case we need
      # to translate an alias or a version
      set parentlist [split $mod /]
      set findmod [lindex $parentlist 0]
      # if searched mod is an empty or flat element append wildcard character
      # to match anything starting with mod
      set wild [expr {[isInList $search wild] ? 1 : 0}]
      if {$wild && [llength $parentlist] <= 1} {
         append findmod *
      }
      # add alias/version definitions from global or user rc to result
      set add_rc_defs [expr {[isInList $search rc_defs_included] ? 1 : 0}]
      if {!$fetch_hidden} {
         set fetch_hidden [isModuleHidden $mod]
         reportDebug "is '$mod' requiring hidden search ($fetch_hidden)"
      }

      # if no indepth mode search, pass the depth level of the search query
      set depthlvl [expr {$indepth ? 0 : [llength $parentlist]}]

      array set found_list [findModules $dir $findmod $depthlvl $fetch_mtime\
         $fetch_hidden]
   }

   # check search query string corresponds to directory
   set querydir [string trimright $mod *]
   set isquerydir [expr {[string index $querydir end] eq {/}}]
   set querydir [string range $querydir 0 end-1]

   array set dir_list {}
   array set mod_list {}
   foreach elt [lsort [array names found_list]] {
      set elt_type [lindex $found_list($elt) 0]
      if {$elt_type eq {modulerc}} {
         if {![info exists g_rcfilesSourced($dir/$elt)]} {
            execute-modulerc $dir/$elt $elt $elt
            # Keep track of already sourced rc files not to run them again
            set g_rcfilesSourced($dir/$elt) 1
         }
      # add other entry kind to the result list
      # also add dirname to results if query name finishes with trailing slash
      } elseif {($wild && [string match $mod* $elt]) || (!$wild && ([string\
         match $mod/* $elt] || [string match $mod $elt])) || ($isquerydir\
         && $elt_type eq {directory} && [string match $querydir $elt])} {
         set mod_list($elt) $found_list($elt)
         # list dirs to rework their definition at the end
         if {$elt_type eq {directory}} {
            set dir_list($elt) 1
         }
      }
   }

   # add versions found when parsing .version or .modulerc files in this
   # directory (skip versions not registered from this directory except if
   # global or user rc definitions should be included)) if they match passed
   # $mod (as for regular modulefiles)
   foreach vers [array names g_moduleVersion -glob $mod*] {
      set versmod $g_moduleVersion($vers)
      if {($dir ne {} && [string first $dir/ $g_sourceVersion($vers)] == 0)\
         || ($add_rc_defs && [info exists g_rcVersion($vers)])} {
         set mod_list($vers) [list version $versmod]
      }
      # no reference add to parent directory structure as versions are virtual

      # add the target of symbolic versions found when parsing .version or
      # .modulerc files if these symbols match passed $mod (as for regular
      # modulefiles). modulefile target of these version symbol should have
      # been found previously to be added
      if {![info exists mod_list($versmod)]} {
         # exception made to hidden modulefile target which should not be
         # found previously as not searched (except if we already look for
         # hidden modules). in case symbolic version matches passed $mod
         # look for this hidden target
         if {$mod eq $vers && !$fetch_hidden && [isModuleHidden $versmod]} {
            array set found_list [findModules $dir $versmod 0 $fetch_mtime 1]
         }

         # symbolic version targets a modulefile most of the time
         if {[info exists found_list($versmod)]} {
            set mod_list($versmod) $found_list($versmod)
         # but sometimes they may target an alias
         } elseif {[info exists g_moduleAlias($versmod)]} {
            lappend matching_versalias $versmod
         # or a virtual module
         } elseif {[info exists g_moduleVirtual($versmod)]} {
            lappend matching_versvirt $versmod
         }
      }
   }

   # add aliases found when parsing .version or .modulerc files in this
   # directory (skip aliases not registered from this directory except if
   # global or user rc definitions should be included) if they match passed
   # $mod (as for regular modulefiles) or if a symbolic versions targeting
   # alias match passed $mod
   set matching_alias [array names g_moduleAlias -glob $mod*]
   if {[info exists matching_versalias]} {
      eval appendNoDupToList matching_alias $matching_versalias
   }
   foreach alias $matching_alias {
      if {($dir ne {} && [string first $dir/ $g_sourceAlias($alias)] == 0)\
         || ($add_rc_defs && [info exists g_rcAlias($alias)])} {
         set mod_list($alias) [list alias $g_moduleAlias($alias)]

         # in case alias overwrites a directory definition
         if {[info exists dir_list($alias)]} {
             unset dir_list($alias)
         }

         # add reference to this alias version in parent structure
         set parentname [file dirname $alias]
         if {[info exists mod_list($parentname)]} {
            lappend mod_list($parentname) [file tail $alias]
         } else {
            # add reference to orphan list if dir does not exist may be added
            # below if dir is virtually set by a virtual deep module
            lappend orphan_list($parentname) [file tail $alias]
         }
      }
   }

   # add virtual mods found when parsing .version or .modulerc files in this
   # directory (skip virtual mods not registered from this directory except if
   # global or user rc definitions should be included) if they match passed
   # $mod (as for regular modulefiles) or if a symbolic versions targeting
   # virtual mod match passed $mod
   set matching_virtual [array names g_moduleVirtual -glob $mod*]
   if {[info exists matching_versvirt]} {
      eval appendNoDupToList matching_virtual $matching_versvirt
   }
   foreach virt $matching_virtual {
      if {($dir ne {} && [string first $dir/ $g_sourceVirtual($virt)] == 0)\
         || ($add_rc_defs && [info exists g_rcVirtual($virt)])} {
         lassign [checkValidModule $g_moduleVirtual($virt)] check_valid\
            check_msg
         switch -- $check_valid {
            true {
               set mtime [expr {$fetch_mtime ? [getFileMtime\
                  $g_moduleVirtual($virt)] : {}}]
               # set mtime at index 1 like a modulefile entry
               set mod_list($virt) [list virtual $mtime\
                  $g_moduleVirtual($virt)]

               set add_ref_to_parent 1
            }
            default {
               # register check error and relative message to get it in
               # case of direct access of this module element, but no
               # registering in parent directory structure as element
               # is not valid
               set mod_list($virt) [list $check_valid $check_msg\
                  $g_moduleVirtual($virt)]

               # no reference to parent list
               set add_ref_to_parent 0
            }
         }

         # in case virtual mod overwrites a directory definition
         if {[info exists dir_list($virt)]} {
             unset dir_list($virt)
         }

         # add reference to this virtual mod in parent structure
         if {$add_ref_to_parent} {
            set parentname [file dirname $virt]
            set elt [file tail $virt]

            # initialize virtual parent structure if it does not exist
            if {![info exists mod_list($parentname)]} {
               # loop until reaching an existing or a top entry
               while {![info exists mod_list($parentname)]\
                  && $parentname ne {.}} {
                  # create virtual directory entry
                  set mod_list($parentname) [list directory $elt]
                  set dir_list($parentname) 1

                  set elt [file tail $parentname]
                  set parentname [file dirname $parentname]
               }
               # add reference to reached existing entry
               if {[info exists mod_list($parentname)]} {
                  lappend mod_list($parentname) $elt
               }
            } else {
               lappend mod_list($parentname) $elt
            }
         }
      }
   }

   # integrate aliases defined in orphan directories if these dirs have been
   # virtually created by a virtual module reference
   foreach dir [array names orphan_list] {
      if {[info exists mod_list($dir)]} {
         set mod_list($dir) [concat $mod_list($dir) $orphan_list($dir)]
      }
   }

   # work on directories integrated in the result list by registering
   # default element in this dir and list of all child elements dictionary
   # sorted, so last element in dir is also last element in this list
   # this treatment happen at the end to find all directory entries in
   # result list (alias and virtual included)
   foreach dir [lsort [array names dir_list]] {
      set elt_list [lsort -dictionary [lrange $mod_list($dir) 1 end]]
      # remove dir from list if it is empty
      if {[llength $elt_list] == 0} {
         unset mod_list($dir)
         # rework upper directories content if registered
         while {[set par_dir [file dirname $dir]] ne {.}\
            && [info exists mod_list($par_dir)]} {
            set dir_name [file tail $dir]
            set dir $par_dir
            # quit if something has overwritten the directory definition
            if {[lindex $mod_list($dir) 0] ne {directory}} {
               break
            }
            # get upper dir content without empty dir (as dir_list is sorted
            # parent dir information have already been consolidated)
            set elt_list [lsearch -all -inline -not -exact [lrange\
               $mod_list($dir) 2 end] $dir_name]
            # remove also parent dir if it becomes empty
            if {[llength $elt_list] == 0} {
               unset mod_list($dir)
            } else {
               # change default by last element if empty dir was default
               set dfl_elt [lindex $mod_list($dir) 1]
               if {$dfl_elt eq $dir_name} {
                  set dfl_elt [lindex $elt_list end]
               }
               set mod_list($dir) [concat [list directory $dfl_elt]\
                  $elt_list]
               # no need to update upper directory as this one persists
               break
            }
         }
      } else {
         # get default element (defined or implicit)
         set dfl_elt [if {[info exists g_resolvedPath($dir)]} {file tail\
            $g_resolvedPath($dir)} {lindex $elt_list end}]
         set mod_list($dir) [concat [list directory $dfl_elt] $elt_list]
      }
   }

   # now all modulefiles are settled (regular, symbol, alias, virtual) only
   # keep those found at search query depth level if 'noindepth' mode asked
   if {!$indepth} {
      # remove entries with more filename path separator than query pattern
      set lastqslash [expr {[string last / $mod] + 1}]
      foreach elt [array names mod_list] {
         if {[string first / $elt $lastqslash] != -1} {
            unset mod_list($elt)
         }
      }
   }

   reportDebug "got [array names mod_list]"
   return [array get mod_list]
}

# format an element with its tags for display in a list
proc formatListEltToDisplay {elt eltsgr eltsuffix tag_list tagsgr show_tags\
   sgrdef {matchmap {}}} {
   set disp $elt$eltsuffix
   # hightlight matching substring
   if {$matchmap ne {}} {
      set dispsgr [sgr $eltsgr [string map $matchmap $elt]]
   } else {
      set dispsgr [sgr $eltsgr $elt]
   }
   if {$show_tags} {
      # display default tag graphically over element name
      if {[set defidx [lsearch -exact $tag_list default]] != -1 && $sgrdef} {
         set tag_list [lreplace $tag_list $defidx $defidx]
         set dispsgr [sgr de $dispsgr]
      }

      # format remaining tag list
      if {[llength $tag_list] > 0} {
         append disp "([join $tag_list :])"
         set tagssgr [sgr se (]
         foreach tag $tag_list {
            if {![info exists colonsgr]} {
               set colonsgr [sgr se :]
            } else {
               append tagssgr $colonsgr
            }
            append tagssgr [sgr $tagsgr $tag]
         }
         append tagssgr [sgr se )]
         append dispsgr $eltsuffix$tagssgr
      } else {
         append dispsgr $eltsuffix
      }
   } else {
      append dispsgr $eltsuffix
   }
   return [list $disp $dispsgr]
}

# format an element with its tags for a long/detailled display in a list
proc formatListEltToLongDisplay {elt eltsgr eltsuffix tag_list tagsgr mtime\
   sgrdef {matchmap {}}} {
   set disp $elt$eltsuffix
   set displen [string length $disp]
   # hightlight matching substring
   if {$matchmap ne {}} {
      set dispsgr [sgr $eltsgr [string map $matchmap $elt]]
   } else {
      set dispsgr [sgr $eltsgr $elt]
   }
   # display default tag graphically over element name
   if {[set defidx [lsearch -exact $tag_list default]] != -1 && $sgrdef} {
      set tag_list [lreplace $tag_list $defidx $defidx]
      set dispsgr [sgr de $dispsgr]
   }
   # format remaining tag list
   if {[llength $tag_list] > 0} {
      set tagslen [string length [join $tag_list :]]
      foreach tag $tag_list {
         if {![info exists colonsgr]} {
            set colonsgr [sgr se :]
         } else {
            append tagssgr $colonsgr
         }
         append tagssgr [sgr $tagsgr $tag]
      }
   } else {
      set tagssgr {}
      set tagslen 0
   }
   set nbws1 [expr {40 - $displen}]
   set nbws2 [expr {20 - $tagslen + [expr {$nbws1 < 0 ? $nbws1 : 0}]}]
   return [list $disp $dispsgr$eltsuffix[string repeat { }\
      $nbws1]$tagssgr[string repeat { } $nbws2]$mtime]
}

# Prepare a map list to translate later on a substring in its highlighted
# counterpart. Translate substring after right trimming it from wildcard
# characters. No translation map is returned if hightlight rendering is
# disabled or if some wildcard characters persist after the trim.
proc prepareMapToHightlightSubstr {substr} {
   set m [string trimright $substr {*?}]
   return [expr {[sgr hi {}] ne {} && $m ne {} && [string first * $m] == -1\
      && [string first ? $m] == -1 ? [list $m [sgr hi $m]] : {}}]
}

# Finds all module versions for mod in the module path dir
proc listModules {dir mod show_mtime filter search} {
   global flag_default_mf flag_default_dir

   reportDebug "get '$mod' in $dir (show_mtime=$show_mtime, filter=$filter,\
      search=$search)"

   # get module list
   # as we treat a full directory content do not exit on an error
   # raised from one modulerc file
   array set mod_list [getModules $dir $mod $show_mtime $search]

   # in depth search performed or not
   set indepth [expr {[isInList $search noindepth] ? 0 : 1}]

   # extract directory name specified in search query string if any
   set querydir [string trimright $mod *]
   set isquerydir [expr {[string index $querydir end] eq {/}}]
   set querydir [string range $querydir 0 end-1]

   # no filtering when in depth disabled and query targets modulepath root
   set filtering [expr {$filter ne {} && ($indepth || [string first / $mod]\
      != -1)}]

   # prepare results for display
   set alias_colored [expr {[sgr al {}] ne {}}]
   set default_colored [expr {[sgr de {}] ne {}}]
   set matchmap [prepareMapToHightlightSubstr $mod]
   set clean_list {}
   foreach elt [array names mod_list] {
      set elt_type [lindex $mod_list($elt) 0]

      set add_to_clean_list 1
      if {$filtering} {
         # only analyze directories or modulefile at the root in case of
         # result filtering. depending on filter kind the selection of the
         # modulefile to display will be made using the definition
         # information of its upper directory
         if {$elt_type eq {directory}} {
            switch -- $filter {
               onlydefaults {
                  set elt_vers [lindex $mod_list($elt) 1]
               }
               onlylatest {
                  set elt_vers [lindex $mod_list($elt) end]
               }
            }
            # switch to selected modulefile to display
            append elt /$elt_vers
            # verify it exists elsewhere skip result for this directory
            if {![info exists mod_list($elt)]} {
               continue
            }
            set elt_type [lindex $mod_list($elt) 0]
            # skip if directory selected, will be looked at in a next round
            if {$elt_type eq {directory}} {
               set add_to_clean_list 0
            }
         } elseif {[file dirname $elt] ne {.}} {
            set add_to_clean_list 0
         }

         if {$add_to_clean_list} {
            set tag_list [getVersAliasList $elt]
         }
      } else {
         set tag_list [getVersAliasList $elt]
         # do not add a dir if it does not hold tags and depth mode is enabled
         # or if search query corresponds to dir: only its content is relevant
         if {$elt_type eq {directory} && (($indepth && [llength $tag_list]\
            == 0) || ($isquerydir && [string match $querydir $elt]))} {
            set add_to_clean_list 0
         }
      }

      if {$add_to_clean_list} {
         set dispsgr {}
         # ignore "version" entries as symbolic version are treated
         # along to their relative modulefile not independently
         switch -- $elt_type {
            directory {
               if {$show_mtime} {
                  # append / char after name to clearly indicate this is a dir
                  lassign [formatListEltToLongDisplay $elt di / $tag_list sy\
                     {} $default_colored $matchmap] disp dispsgr
               } else {
                  lassign [formatListEltToDisplay $elt di / $tag_list sy\
                     $flag_default_dir $default_colored $matchmap] disp\
                     dispsgr
               }
            }
            modulefile - virtual {
               if {$show_mtime} {
                  # add to display file modification time in addition
                  # to potential tags
                  lassign [formatListEltToLongDisplay $elt {} {} $tag_list sy\
                     [clock format [lindex $mod_list($elt) 1] -format\
                     {%Y/%m/%d %H:%M:%S}] $default_colored $matchmap] disp\
                     dispsgr
               } else {
                  lassign [formatListEltToDisplay $elt {} {} $tag_list sy\
                     $flag_default_mf $default_colored $matchmap] disp dispsgr
               }
            }
            alias {
               if {$show_mtime} {
                  lassign [formatListEltToLongDisplay $elt al " -> [lindex\
                     $mod_list($elt) 1]" $tag_list sy {} $default_colored\
                     $matchmap] disp dispsgr
               } else {
                  # add a '@' tag to indicate elt is an alias if not colored
                  if {!$alias_colored} {
                     lappend tag_list @
                  }
                  lassign [formatListEltToDisplay $elt al {} $tag_list sy\
                     $flag_default_mf $default_colored $matchmap] disp dispsgr
               }
            }
         }
         if {$dispsgr ne {}} {
            lappend clean_list $disp
            set sgrmap($disp) $dispsgr
         }
      }
   }

   set display_list {}
   set len_list {}
   set max_len 0
   # always dictionary-sort results
   foreach disp [lsort -dictionary $clean_list] {
      # compute display element length list on sorted result
      lappend display_list $sgrmap($disp)
      lappend len_list [set len [string length $disp]]
      if {$len > $max_len} {
         set max_len $len
      }
   }

   reportDebug "Returning $display_list"
   return [list $display_list $len_list $max_len]
}

proc showModulePath {} {
   set modpathlist [getModulePathList]
   if {[llength $modpathlist] > 0} {
      report {Search path for module files (in search order):}
      foreach path $modpathlist {
         report "  [sgr mp $path]"
      }
   } else {
      reportWarning {No directories on module search path}
   }
}

proc displayTableHeader {sgrkey args} {
   foreach {title col_len} $args {
      set col "- [sgr $sgrkey $title] "
      append col [string repeat - [expr {$col_len - [string length $title] -\
         3}]]
      lappend col_list $col
   }

   report [join $col_list .]
}

proc displaySeparatorLine {{title {}} {sgrkey {}}} {
   set tty_cols [getTtyColumns]
   if {$title eq {}} {
      # adapt length if screen width is very small
      set max_rep 67
      set rep [expr {$tty_cols > $max_rep ? $max_rep : $tty_cols}]
      report [string repeat - $rep]
   } else {
      set len [string length $title]
      # max expr function is not supported in Tcl8.4 and earlier
      if {[set lrep [expr {($tty_cols - $len - 2)/2}]] < 1} {
         set lrep 1
      }
      if {[set rrep [expr {$tty_cols - $len - 2 - $lrep}]] < 1} {
         set rrep 1
      }
      report "[string repeat - $lrep] [sgr $sgrkey $title] [string repeat -\
         $rrep]"
   }
}

# get a list of elements and print them in a column or in a
# one-per-line fashion
proc displayElementList {header sgrkey hstyle one_per_line display_idx\
   display_list {len_list {}} {max_len 0}} {
   set elt_cnt [llength $display_list]
   reportDebug "header=$header, sgrkey=$sgrkey, hstyle=$hstyle,\
      elt_cnt=$elt_cnt, max_len=$max_len, one_per_line=$one_per_line,\
      display_idx=$display_idx"

   # end proc if no element are to print
   if {$elt_cnt == 0} {
      return
   }

   # display header if any provided
   if {$header ne {noheader}} {
      if {$hstyle eq {sepline}} {
         displaySeparatorLine $header $sgrkey
      } else {
         report [sgr $sgrkey $header]:
      }
   }

   # display one element per line
   if {$one_per_line} {
      if {$display_idx} {
         set idx 1
         foreach elt $display_list {
            append displist [format {%2d) %s } $idx $elt] \n
            incr idx
         }
      } else {
         append displist [join $display_list \n] \n
      }
   # elsewhere display elements in columns
   } else {
      if {$display_idx} {
         # save room for numbers and spacing: 2 digits + ) + space
         set elt_prefix_len 4
      } else {
         set elt_prefix_len 0
      }
      # save room for two spaces after element
      set elt_suffix_len 2

      # compute rows*cols grid size with optimized column number
      # the size of each column is computed to display as much column
      # as possible on each line
      incr max_len $elt_suffix_len
      foreach len $len_list {
         lappend elt_len [incr len $elt_suffix_len]
      }

      set tty_cols [getTtyColumns]
      # find valid grid by starting with non-optimized solution where each
      # column length is equal to the length of the biggest element to display
      set cur_cols [expr {int(($tty_cols - $elt_prefix_len) / $max_len)}]
      # when display is found too short to display even one column
      if {$cur_cols == 0} {
         set cols 1
         set rows $elt_cnt
         array set col_width [list 0 $max_len]
      } else {
         set cols 0
         set rows 0
      }
      set last_round 0
      set restart_loop 0
      while {$cur_cols > $cols} {
         if {!$restart_loop} {
            if {$last_round} {
               incr cur_rows
            } else {
               set cur_rows [expr {int(ceil(double($elt_cnt) / $cur_cols))}]
            }
            for {set i 0} {$i < $cur_cols} {incr i} {
               set cur_col_width($i) 0
            }
            for {set i 0} {$i < $cur_rows} {incr i} {
               set row_width($i) 0
            }
            set istart 0
         } else {
            set istart [expr {$col * $cur_rows}]
            # only remove width of elements from current col
            for {set row 0} {$row < ($i % $cur_rows)} {incr row} {
               incr row_width($row) -[expr {$pre_col_width + $elt_prefix_len}]
            }
         }
         set restart_loop 0
         for {set i $istart} {$i < $elt_cnt} {incr i} {
            set col [expr {int($i / $cur_rows)}]
            set row [expr {$i % $cur_rows}]
            # restart loop if a column width change
            if {[lindex $elt_len $i] > $cur_col_width($col)} {
               set pre_col_width $cur_col_width($col)
               set cur_col_width($col) [lindex $elt_len $i]
               set restart_loop 1
               break
            }
            # end search of maximum number of columns if computed row width
            # is larger than terminal width
            if {[incr row_width($row) +[expr {$cur_col_width($col) \
               + $elt_prefix_len}]] > $tty_cols} {
               # start last optimization pass by increasing row number until
               # reaching number used for previous column number, by doing so
               # this number of column may pass in terminal width, if not
               # fallback to previous number of column
               if {$last_round && $cur_rows == $rows} {
                  incr cur_cols -1
               } else {
                  set last_round 1
               }
               break
            }
         }
         # went through all elements without reaching terminal width limit so
         # this number of column solution is valid, try next with a greater
         # column number
         if {$i == $elt_cnt} {
            set cols $cur_cols
            set rows $cur_rows
            array set col_width [array get cur_col_width]
            # number of column is fixed if last optimization round has started
            # reach end also if there is only one row of results
            if {!$last_round && $rows > 1} {
               incr cur_cols
            }
         }

      }
      reportDebug list=$display_list
      reportDebug "rows/cols=$rows/$cols,\
         lastcol_item_cnt=[expr {int($elt_cnt % $rows)}]"

      for {set row 0} {$row < $rows} {incr row} {
         for {set col 0} {$col < $cols} {incr col} {
            set index [expr {$col * $rows + $row}]
            if {$index < $elt_cnt} {
               if {$display_idx} {
                  append displist [format "%2d) " [expr {$index +1}]]
               }
               # cannot use 'format' as strings may contain SGR codes
               append displist [lindex $display_list $index][string repeat\
                  { } [expr {$col_width($col) - [lindex $len_list $index]}]]
            }
         }
         append displist \n
      }
   }
   report $displist 1
   reportSeparateNextContent
}

# Return conf value and from where an eventual def value has been overridden
proc displayConfig {val env_var {asked_var {}} {trans {}}} {
   array set transarr $trans

   # get overridden value and know what has overridden it
   if {$asked_var ne {} && [info exists ::$asked_var]} {
      set defby " (cmd-line)"
   } elseif {$env_var ne {} && [info exists ::env($env_var)]} {
      set defby " (env-var)"
   } else {
      set defby {}
   }

   # translate fetched value if translation table exists
   if {[info exists transarr($val)]} {
      set val $transarr($val)
   }

   return $val$defby
}

# build list of what to undo then do to move from an initial list to a target
# list, eventually checking element presence in extra from/to lists
proc getMovementBetweenList {from to {extfrom {}} {extto {}}} {
   reportDebug "from($from) to($to) with extfrom($extfrom) extto($extto)"

   set undo {}
   set do {}

   # determine what element to undo then do
   # to restore a target list from a current list
   # with preservation of the element order
   set imax [if {[llength $to] > [llength $from]} {llength $to} {llength\
      $from}]
   set list_equal 1
   for {set i 0} {$i < $imax} {incr i} {
      set to_obj [lindex $to $i]
      set from_obj [lindex $from $i]
      # check from/to element presence in extra from/to list
      set in_extfrom [isInList $extfrom $from_obj]
      set in_extto [isInList $extto $to_obj]
      # are elts the sames and are both part of or missing from extra lists
      if {$to_obj ne $from_obj || $in_extfrom != $in_extto} {
         set list_equal 0
      }
      if {$list_equal == 0} {
         if {$to_obj ne {}} {
            lappend do $to_obj
         }
         if {$from_obj ne {}} {
            lappend undo $from_obj
         }
      }
   }

   return [list $undo $do]
}

# build list of currently loaded modules where modulename is registered minus
# module version if loaded version is the default one. a helper list may be
# provided and looked at prior to module search
proc getSimplifiedLoadedModuleList {{helper_raw_list {}}\
   {helper_list {}}} {
   reportDebug called.

   set curr_mod_list {}
   set curr_nuasked_list {}
   set modpathlist [getModulePathList]
   foreach mod [getLoadedModuleList] {
      # if mod found in a previous LOADEDMODULES list use simplified
      # version of this module found in relative helper list (previously
      # computed simplified list)
      if {[set helper_idx [lsearch -exact $helper_raw_list $mod]] != -1} {
         set simplemod [lindex $helper_list $helper_idx]
      # look through modpaths for a simplified mod name if not full path
      } elseif {![isModuleFullPath $mod] && [llength $modpathlist] > 0} {
         set modfile [getModulefileFromLoadedModule $mod]
         set parentmod [file dirname $mod]
         set simplemod $mod
         # simplify to parent name as long as it resolves to current mod
         while {$parentmod ne {.}} {
            lassign [getPathToModule $parentmod $modpathlist] parentfile
            if {$parentfile eq $modfile} {
               set simplemod $parentmod
               set parentmod [file dirname $parentmod]
            } else {
               set parentmod .
            }
         }
      } else {
         set simplemod $mod
      }
      lappend curr_mod_list $simplemod
      # record not user asked module list in simplified version form
      if {![isModuleUserAsked $mod]} {
         lappend curr_nuasked_list $simplemod
      }
   }

   return [list $curr_mod_list $curr_nuasked_list]
}

# should modulefile version be pinned when saving collection?
proc pinVersionInCollection {} {
   return [expr {[get-env MODULES_COLLECTION_PIN_VERSION] eq {1}}]
}

# return saved collections found in user directory which corresponds to
# enabled collection target if any set.
proc findCollections {} {
   if {[info exists ::env(HOME)]} {
      set coll_search $::env(HOME)/.module/*
   } else {
      reportErrorAndExit {HOME not defined}
   }

   # find saved collections (matching target suffix)
   # a target is a domain on which a collection is only valid.
   # when a target is set, only the collections made for that target
   # will be available to list and restore, and saving will register
   # the target footprint
   set colltarget [get-env MODULES_COLLECTION_TARGET]
   if {$colltarget ne {}} {
      append coll_search .$colltarget
   }

   # workaround 'glob -nocomplain' which does not return permission
   # error on Tcl 8.4, so we need to avoid raising error if no match
   # glob excludes by default files starting with "."
   if {[catch {set coll_list [glob $coll_search]} errMsg ]} {
      if {$errMsg eq "no files matched glob pattern \"$coll_search\""} {
         set coll_list {}
      } else {
         reportErrorAndExit "Cannot access collection directory.\n$errMsg"
      }
   }

   return $coll_list
}

# get filename corresponding to collection name provided as argument.
# name provided may already be a file name. collection description name
# (with target info if any) is returned along with collection filename
proc getCollectionFilename {coll} {
   # initialize description with collection name
   set colldesc $coll

   if {$coll eq {}} {
      reportErrorAndExit {Invalid empty collection name}
   # is collection a filepath
   } elseif {[string first / $coll] > -1} {
      # collection target has no influence when
      # collection is specified as a filepath
      set collfile $coll
   # elsewhere collection is a name
   } elseif {[info exists ::env(HOME)]} {
      set collfile $::env(HOME)/.module/$coll
      # if a target is set, append the suffix corresponding
      # to this target to the collection file name
      set colltarget [get-env MODULES_COLLECTION_TARGET]
      if {$colltarget ne {}} {
         append collfile .$colltarget
         # add knowledge of collection target on description
         append colldesc " (for target \"$colltarget\")"
      }
   } else {
      reportErrorAndExit {HOME not defined}
   }

   return [list $collfile $colldesc]
}

# generate collection content based on provided path and module lists
proc formatCollectionContent {path_list mod_list nuasked_list {sgr 0}} {
   set content {}

   # graphically enhance module command if asked
   set modcmd [expr {$sgr ? [sgr cm module] : {module}}]

   # start collection content with modulepaths
   foreach path $path_list {
      # 'module use' prepends paths by default so we clarify
      # path order here with --append flag
      append content "$modcmd use --append $path" \n
   }

   # then add modules
   foreach mod $mod_list {
      # mark modules not asked by user to restore the user asked state
      set opt [expr {[isInList $nuasked_list $mod] ? {--notuasked } : {}}]
      append content "$modcmd load $opt$mod" \n
   }

   return $content
}

# read given collection file and return the path and module lists it defines
proc readCollectionContent {collfile colldesc} {
   # init lists (maybe coll does not set mod to load)
   set path_list {}
   set mod_list {}
   set nuasked_list {}

   # read file
   if {[catch {
      set fdata [split [readFile $collfile] \n]
   } errMsg ]} {
      reportErrorAndExit "Collection $colldesc cannot be read.\n$errMsg"
   }

   # analyze collection content
   foreach fline $fdata {
      if {[regexp {module use (.*)$} $fline match patharg] == 1} {
         # paths are appended by default
         set stuff_path append
         # manage with "split" multiple paths and path options
         # specified on single line, for instance:
         # module use --append path1 path2 path3
         foreach path [split $patharg] {
            # following path is asked to be appended
            if {($path eq {--append}) || ($path eq {-a})\
               || ($path eq {-append})} {
               set stuff_path append
            # following path is asked to be prepended
            # collection generated with 'save' does not prepend
            } elseif {($path eq {--prepend}) || ($path eq {-p})\
               || ($path eq {-prepend})} {
               set stuff_path prepend
            } else {
               # ensure given path is absolute to be able to correctly
               # compare with paths registered in MODULEPATH
               set path [getAbsolutePath $path]
               # add path to end of list
               if {$stuff_path eq {append}} {
                  lappend path_list $path
               # insert path to first position
               } else {
                  set path_list [linsert $path_list 0 $path]
               }
            }
         }
      } elseif {[regexp {module load (.*)$} $fline match modarg] == 1} {
         # manage multiple modules specified on a single line with "split",
         # for instance: module load mod1 mod2 mod3
         set arglist [split $modarg]
         # make a list of modules that were not directly asked by user
         set cleanlist [lsearch -all -inline -not -exact $arglist\
            --notuasked]
         if {[llength $arglist] != [llength $cleanlist]} {
            set nuasked_list [concat $nuasked_list $cleanlist]
         }
         set mod_list [concat $mod_list $cleanlist]
      }
   }

   return [list $path_list $mod_list $nuasked_list]
}

# analyze arg list passed to a module cmd to set options
proc parseModuleCommandArgs {cmd args} {
   set show_oneperline 0
   set show_mtime 0
   set show_filter {}
   set search_filter [expr {[getAvailInDepth] ? {} : {noindepth}}]
   set dump_state 0
   set otherargs {}

   # parse argument list
   foreach arg $args {
      switch -glob -- $arg {
         -t - --terse {
            set show_oneperline 1
            set show_mtime 0
         }
         -l - --long {
            set show_mtime 1
            set show_oneperline 0
         }
         -d - --default {
            # in case of *-path command, -d means --delim
            if {$arg eq {-d} && [string match *-path $cmd]} {
               lappend otherargs $arg
            } else {
               set show_filter onlydefaults
            }
         }
         -L - --latest {
            set show_filter onlylatest
         }
         --indepth {
            # empty value means 'in depth' as it is default behavior
            set search_filter {}
         }
         --no-indepth {
            set search_filter noindepth
         }
         --dump-state {
            set dump_state 1
         }
         --auto - --no-auto - -f - --force {
            reportWarning "Unsupported option '$arg'"
         }
         default {
            lappend otherargs $arg
         }
      }
   }

   reportDebug "(show_oneperline=$show_oneperline, show_mtime=$show_mtime,\
      show_filter=$show_filter, search_filter=$search_filter,\
      dump_state=$dump_state, otherargs=$otherargs)"
   return [list $show_oneperline $show_mtime $show_filter $search_filter\
      $dump_state $otherargs]
}

# unload phase of a list of modules reload process
proc reloadModuleListUnloadPhase {lmname {force 0} {errmsgtpl {Reload of\
   _MOD_ failed}} {context unload}} {
   upvar $lmname lmlist
   # unload one by one to ensure same behavior whatever auto_handling state
   foreach mod [lreverse $lmlist] {
      # save user asked state before it vanishes
      set isuasked($mod) [isModuleUserAsked $mod]
      # force unload even if requiring mods are not part of the unload list
      # (violation state) as modules are loaded again just after
      if {[cmdModuleUnload $context match 0 1 0 0 $mod]} {
         # avoid failing module on load phase
         set lmlist [replaceFromList $lmlist $mod]
         set errMsg [string map [list _MOD_ $mod] $errmsgtpl]
         if {$force} {
            reportWarning $errMsg 1
         # stop if one unload fails unless force mode enabled
         } else {
            error $errMsg
         }
      }
   }
   return [array get isuasked]
}

# load phase of a list of modules reload process
proc reloadModuleListLoadPhase {lmname isuaskedlist {force 0} {errmsgtpl\
   {Reload of _MOD_ failed}} {context load}} {
   upvar $lmname lmlist
   array set isuasked $isuaskedlist

   # loads are made with auto handling mode disabled to avoid disturbances
   # from a missing prereq automatically reloaded, so these module loads may
   # fail as prereq may not be satisfied anymore
   set ::g_auto_handling 0
   foreach mod $lmlist {
      # reload module with user asked property preserved
      if {[cmdModuleLoad $context $isuasked($mod) $mod]} {
         set errMsg [string map [list _MOD_ $mod] $errmsgtpl]
         if {$force} {
            reportWarning $errMsg 1
         # stop if one load fails unless force mode enabled
         } else {
            error $errMsg
         }
      }
   }
   set ::g_auto_handling 1
}

########################################################################
# command line commands
#
proc cmdModuleList {show_oneperline show_mtime} {
   set loadedmodlist [getLoadedModuleList]

   if {[llength $loadedmodlist] == 0} {
      report {No Modulefiles Currently Loaded.}
   } else {
      set display_list {}
      set default_colored [expr {[sgr de {}] ne {}}]
      set len_list {}
      set max_len 0
      foreach mod $loadedmodlist {
         if {$show_oneperline} {
            lappend display_list $mod
         } else {
            set modfile [getModulefileFromLoadedModule $mod]
            # skip rc find and execution if mod is registered as full path
            if {[isModuleFullPath $mod]} {
               set mtime [getFileMtime $mod]
               set tag_list {}
            # or if loaded module is a virtual module
            } elseif {[isModuleVirtual $mod $modfile]} {
               set mtime [getFileMtime $modfile]
               set tag_list {}
            } else {
               # call getModules to find and execute rc files for this mod
               set dir [getModulepathFromModuleName $modfile $mod]
               array set mod_list [getModules $dir $mod $show_mtime]
               # fetch info only if mod found
               if {[info exists mod_list($mod)]} {
                  set mtime [lindex $mod_list($mod) 1]
                  set tag_list [getVersAliasList $mod]
               } else {
                  set tag_list {}
               }
            }

            if {$show_mtime} {
               if {[info exists mtime]} {
                  set clock_mtime [clock format $mtime -format\
                     {%Y/%m/%d %H:%M:%S}]
                  unset mtime
               } else {
                  set clock_mtime {}
               }

               # add to display file modification time in addition to tags
               lassign [formatListEltToLongDisplay $mod {} {} $tag_list sy\
                  $clock_mtime $default_colored] disp dispsgr
            } else {
               lassign [formatListEltToDisplay $mod {} {} $tag_list sy 1\
                  $default_colored] disp dispsgr
               lappend len_list [set len [string length $disp]]
               if {$len > $max_len} {
                  set max_len $len
               }
            }
            lappend display_list $dispsgr
         }
      }

      if {$show_mtime} {
         displayTableHeader hi Package 39 Versions 19 {Last mod.} 19
      }
      report {Currently Loaded Modulefiles:}
      if {$show_mtime || $show_oneperline} {
         set display_idx 0
         set one_per_line 1
      } else {
         set display_idx 1
         set one_per_line 0
      }

      displayElementList noheader {} {} $one_per_line $display_idx\
         $display_list $len_list $max_len
   }
}

proc cmdModuleDisplay {args} {
   reportDebug "displaying $args"

   pushMode display
   set first_report 1
   foreach mod $args {
      lassign [getPathToModule $mod] modfile modname
      if {$modfile ne {}} {
         # only one separator lines between 2 modules
         if {$first_report} {
            displaySeparatorLine
            set first_report 0
         }
         report [sgr hi $modfile]:\n
         execute-modulefile $modfile $modname $mod
         displaySeparatorLine
      }
   }
   popMode
}

proc cmdModulePaths {mod} {
   reportDebug ($mod)

   set dir_list [getModulePathList exiterronundef]
   foreach dir $dir_list {
      array unset mod_list
      array set mod_list [getModules $dir $mod 0 rc_defs_included]

      # prepare list of dirs for alias/symbol target search, will first search
      # in currently looked dir, then in other dirs following precedence order
      set target_dir_list [concat [list $dir] [replaceFromList $dir_list\
         $dir]]

      # build list of modulefile to print
      foreach elt [array names mod_list] {
         switch -- [lindex $mod_list($elt) 0] {
            modulefile {
               lappend ::g_return_text $dir/$elt
            }
            virtual {
               lappend ::g_return_text [lindex $mod_list($elt) 2]
            }
            alias - version {
               # resolve alias target
               set aliastarget [lindex $mod_list($elt) 1]
               lassign [getPathToModule $aliastarget $target_dir_list]\
                  modfile modname
               # add module target as result instead of alias
               if {$modfile ne {} && ![info exists mod_list($modname)]} {
                  lappend ::g_return_text $modfile
               }
            }
         }
      }
   }

   # sort results if any and remove duplicates
   if {[info exists ::g_return_text]} {
      set ::g_return_text [lsort -dictionary -unique $::g_return_text]
   } else {
      # set empty value to return empty if no result
      set ::g_return_text {}
   }
}

proc cmdModulePath {mod} {
   reportDebug ($mod)
   lassign [getPathToModule $mod] modfile modname
   # if no result set empty value to return empty
   set ::g_return_text $modfile
}

proc cmdModuleWhatIs {{mod {}}} {
   cmdModuleSearch $mod {}
}

proc cmdModuleApropos {{search {}}} {
   cmdModuleSearch {} $search
}

proc cmdModuleSearch {{mod {}} {search {}}} {
   reportDebug "($mod, $search)"

   # disable error reporting to avoid modulefile errors
   # to mix with valid search results
   inhibitErrorReport

   lappend searchmod rc_defs_included
   if {$mod eq {}} {
      lappend searchmod wild
   }
   set foundmod 0
   pushMode whatis
   set dir_list [getModulePathList exiterronundef]
   foreach dir $dir_list {
      array unset mod_list
      array set mod_list [getModules $dir $mod 0 $searchmod]
      array unset interp_list
      array set interp_list {}

      # build list of modulefile to interpret
      foreach elt [array names mod_list] {
         switch -- [lindex $mod_list($elt) 0] {
            modulefile {
               set interp_list($elt) $dir/$elt
               # register module name in a global list (shared across
               # modulepaths) to get hints when solving aliases/version
               set full_list($elt) 1
            }
            virtual {
               set interp_list($elt) [lindex $mod_list($elt) 2]
               set full_list($elt) 1
            }
            alias - version {
               # resolve alias target
               set elt_target [lindex $mod_list($elt) 1]
               if {![info exists full_list($elt_target)]} {
                  lassign [getPathToModule $elt_target $dir]\
                     modfile modname issuetype issuemsg
                  # add module target as result instead of alias
                  if {$modfile ne {} && ![info exists mod_list($modname)]} {
                     set interp_list($modname) $modfile
                     set full_list($modname) 1
                  } elseif {$modfile eq {}} {
                     # if module target not found in current modulepath add to
                     # list for global search after initial modulepath lookup
                     if {[string first {Unable to locate} $issuemsg] == 0} {
                        set extra_search($modname) [list $dir [expr {$elt eq\
                           $mod}]]
                     # register resolution error if alias name matches search
                     } elseif {$elt eq $mod} {
                        set err_list($modname) [list $issuetype $issuemsg]
                     }
                  }
               }
            }
            invalid - accesserr {
               # register any error occuring on element matching search
               if {$elt eq $mod} {
                  set err_list($elt) $mod_list($elt)
               }
            }
         }
      }

      # in case during modulepath lookup we find an alias target we were
      # looking for in previous modulepath, remove this element from global
      # search list
      foreach elt [array names extra_search] {
         if {[info exists full_list($elt)]} {
            unset extra_search($elt)
         }
      }

      # save results from this modulepath for interpretation step as there
      # is an extra round of search to match missing alias target, we cannot
      # process modulefiles found immediately
      if {[array size interp_list] > 0} {
         set interp_save($dir) [array get interp_list]
      }
   }

   # find target of aliases in all modulepath except the one already tried
   foreach elt [array names extra_search] {
      lassign [getPathToModule $elt {} no [lindex $extra_search($elt) 0]]\
         modfile modname issuetype issuemsg issuefile
      # found target so append it to results in corresponding modulepath
      if {$modfile ne {}} {
         # get belonging modulepath dir depending of module kind
         if {[isModuleVirtual $modname $modfile]} {
            set dir [findModulepathFromModulefile\
               $::g_sourceVirtual($modname)]
         } else {
            set dir [getModulepathFromModuleName $modfile $modname]
         }
         array unset interp_list
         if {[info exists interp_save($dir)]} {
            array set interp_list $interp_save($dir)
         }
         set interp_list($modname) $modfile
         set interp_save($dir) [array get interp_list]
      # register resolution error if primal alias name matches search
      } elseif {$modfile eq {} && [lindex $extra_search($elt) 1]} {
         set err_list($modname) [list $issuetype $issuemsg $issuefile]
      }
   }

   # prepare string translation to highlight search query string
   set matchmodmap [prepareMapToHightlightSubstr $mod]
   set matchsearchmap [prepareMapToHightlightSubstr $search]

   # interpret all modulefile we got for each modulepath
   foreach dir $dir_list {
      if {[info exists interp_save($dir)]} {
         array unset interp_list
         array set interp_list $interp_save($dir)
         set foundmod 1
         set display_list {}
         # interpret every modulefiles obtained to get their whatis text
         foreach elt [lsort -dictionary [array names interp_list]] {
            set ::g_whatis {}
            execute-modulefile $interp_list($elt) $elt $elt

            # treat whatis as a multi-line text
            if {$search eq {} || [regexp -nocase $search $::g_whatis]} {
               set eltsgr [string map $matchmodmap $elt]
               foreach line $::g_whatis {
                  set linesgr [string map $matchsearchmap $line]
                  lappend display_list "[string repeat { } [expr {20 -\
                     [string length $elt]}]]$eltsgr: $linesgr"
               }
            }
         }

         displayElementList $dir mp sepline 1 0 $display_list
      }
   }
   popMode

   reenableErrorReport

   # report errors if a modulefile was searched but not found
   if {$mod ne {} && !$foundmod} {
      # no error registered means nothing was found to match search
      if {![array exists err_list]} {
         set err_list($mod) [list none "Unable to locate a modulefile for\
            '$mod'"]
      }
      foreach elt [array names err_list] {
         eval reportIssue $err_list($elt)
      }
   }
}

proc cmdModuleSwitch {uasked old {new {}}} {
   # if a single name is provided it matches for the module to load and in
   # this case the module to unload is searched to find the closest match
   # (loaded module that shares at least the same root name)
   if {$new eq {}} {
      set new $old
      set unload_match close
   } else {
      set unload_match match
   }
   # save orig names to register them as deps if called from modulefile
   set argnew $new
   set argold [expr {$new eq $old ? {} : $old}]

   reportDebug "old='$old' new='$new' (uasked=$uasked)"

   # record sumup messages from underlying unload/load actions under the same
   # switch message record id to report (evaluation messages still go under
   # their respective unload/load block
   pushMsgRecordId switch-$old-$new-[getEvalModuleStackDepth]

   set ret [cmdModuleUnload swunload $unload_match 1 0 0 0 $old]

   # register modulefile to unload as conflict if an unload module is
   # mentionned on this module switch command set in a modulefile
   set orig_auto_handling [getAutoHandling]
   if {!$uasked && $argold ne {}} {
      # temporarily disable auto handling just to record deps, not to try to
      # load or unload them (already tried)
      set ::g_auto_handling 0
      catch {conflict $argold}
      set ::g_auto_handling $orig_auto_handling
   }

   # attempt load and depre reload only if unload succeed
   if {!$ret} {
      cmdModuleLoad swload $uasked $new

      if {[getAutoHandling] && [info exists deprelist] && [llength\
         $deprelist] > 0} {
         # cmdModuleUnload handles the DepUn, UReqUn mechanisms and the unload
         # phase of the DepRe mechanism. List of DepRe mods and their user
         # asked state is set from cmdModuleUnload procedure to be used here
         # for the load phase of the DepRe mechanism.
         # Try DepRe load phase: load failure will not lead to switch failure
         reloadModuleListLoadPhase deprelist [array get isuasked]\
            1 {Reload of dependent _MOD_ failed} depre
      }

      # report a summary of automated evaluations if no error
      reportModuleEval
   }

   # report all recorded sumup messages for this evaluation
   reportMsgRecord "Switching from [sgr hi $old] to [sgr hi $new]"
   popMsgRecordId

   # register modulefile to load as prereq when called from modulefile
   if {!$uasked && !$ret && $argnew ne {}} {
      set ::g_auto_handling 0
      prereq $argnew
      set ::g_auto_handling $orig_auto_handling
   }
}

proc cmdModuleSave {{coll default}} {
   reportDebug $coll

   if {![areModuleConstraintsSatisfied]} {
      reportErrorAndExit {Cannot save collection, some module constraints are\
         not satistied}
   }

   # format collection content, version number of modulefile are saved if
   # version pinning is enabled
   if {[pinVersionInCollection]} {
      set curr_mod_list [getLoadedModuleList]
      set curr_nuasked_list [getLoadedModuleNotUserAskedList]
   } else {
      lassign [getSimplifiedLoadedModuleList] curr_mod_list curr_nuasked_list
   }
   set save [formatCollectionContent [getModulePathList returnempty 0]\
      $curr_mod_list $curr_nuasked_list]

   if { [string length $save] == 0} {
      reportErrorAndExit {Nothing to save in a collection}
   }

   # get coresponding filename and its directory
   lassign [getCollectionFilename $coll] collfile colldesc
   set colldir [file dirname $collfile]

   if {![file exists $colldir]} {
      reportDebug "Creating $colldir"
      file mkdir $colldir
   } elseif {![file isdirectory $colldir]} {
      reportErrorAndExit "$colldir exists but is not a directory"
   }

   reportDebug "Saving $collfile"

   if {[catch {
      set fid [open $collfile w]
      puts $fid $save
      close $fid
   } errMsg ]} {
      reportErrorAndExit "Collection $colldesc cannot be saved.\n$errMsg"
   }
}

proc cmdModuleRestore {{coll default}} {
   reportDebug $coll

   # get coresponding filename
   lassign [getCollectionFilename $coll] collfile colldesc

   if {![file exists $collfile]} {
      reportErrorAndExit "Collection $colldesc cannot be found"
   }

   # read collection
   lassign [readCollectionContent $collfile $colldesc] coll_path_list\
      coll_mod_list coll_nuasked_list

   # collection should at least define a path or a mod
   if {[llength $coll_path_list] == 0 && [llength $coll_mod_list] == 0} {
      reportErrorAndExit "$colldesc is not a valid collection"
   }

   # fetch what is currently loaded
   set curr_path_list [getModulePathList returnempty 0]
   # get current loaded module list in simplified and raw versions
   # these lists may be used later on, see below
   set curr_mod_list_raw [getLoadedModuleList]
   set curr_nuasked_list_raw [getLoadedModuleNotUserAskedList]
   lassign [getSimplifiedLoadedModuleList] curr_mod_list curr_nuasked_list

   # determine what module to unload to restore collection
   # from current situation with preservation of the load order
   lassign [getMovementBetweenList $curr_mod_list $coll_mod_list\
      $curr_nuasked_list $coll_nuasked_list] mod_to_unload mod_to_load
   # determine unload movement with raw loaded list in case versions are
   # pinning in saved collection
   lassign [getMovementBetweenList $curr_mod_list_raw $coll_mod_list\
      $curr_nuasked_list_raw $coll_nuasked_list] mod_to_unload_raw\
      mod_to_load_raw
   if {[llength $mod_to_unload] > [llength $mod_to_unload_raw]} {
      set mod_to_unload $mod_to_unload_raw
   }

   # proceed as well for modulepath
   lassign [getMovementBetweenList $curr_path_list $coll_path_list] \
      path_to_unuse path_to_use

   # set a unique id to record messages related to this evaluation.
   pushMsgRecordId restore-$coll-[getEvalModuleStackDepth]

   # unload modules one by one (no dependency auto unload)
   if {[llength $mod_to_unload] > 0} {
      eval cmdModuleUnload unmo match 0 0 0 0 [lreverse $mod_to_unload]
   }
   # unuse paths
   if {[llength $path_to_unuse] > 0} {
      eval cmdModuleUnuse [lreverse $path_to_unuse]
   }

   # since unloading a module may unload other modules or
   # paths, what to load/use has to be determined after
   # the undo phase, so current situation is fetched again
   set curr_path_list [getModulePathList returnempty 0]

   # here we may be in a situation were no more path is left
   # in module path, so we cannot easily compute the simplified loaded
   # module list. so we provide two helper lists: simplified and raw
   # versions of the loaded module list computed before starting to
   # unload modules. these helper lists may help to learn the
   # simplified counterpart of a loaded module if it was already loaded
   # before starting to unload modules
   lassign [getSimplifiedLoadedModuleList $curr_mod_list_raw $curr_mod_list]\
      curr_mod_list curr_nuasked_list
   set curr_mod_list_raw [getLoadedModuleList]
   set curr_nuasked_list_raw [getLoadedModuleNotUserAskedList]

   # determine what module to load to restore collection
   # from current situation with preservation of the load order
   lassign [getMovementBetweenList $curr_mod_list $coll_mod_list\
      $curr_nuasked_list $coll_nuasked_list] mod_to_unload mod_to_load
   # determine load movement with raw loaded list in case versions are
   # pinning in saved collection
   lassign [getMovementBetweenList $curr_mod_list_raw $coll_mod_list\
      $curr_nuasked_list_raw $coll_nuasked_list] mod_to_unload_raw\
      mod_to_load_raw
   if {[llength $mod_to_load] > [llength $mod_to_load_raw]} {
      set mod_to_load $mod_to_load_raw
   }

   # proceed as well for modulepath
   lassign [getMovementBetweenList $curr_path_list $coll_path_list] \
      path_to_unuse path_to_use

   # use paths
   if {[llength $path_to_use] > 0} {
      # always append path here to guaranty the order
      # computed above in the movement lists
      eval cmdModuleUse --append $path_to_use
   }

   # load modules one by one with user asked state preserved
   foreach mod $mod_to_load {
      cmdModuleLoad lomo [notInList $coll_nuasked_list $mod] $mod
   }

   reportModuleEval
   reportMsgRecord "Restoring collection [sgr hi $colldesc]"
   popMsgRecordId
}

proc cmdModuleSaverm {{coll default}} {
   reportDebug $coll

   # avoid to remove any kind of file with this command
   if {[string first / $coll] > -1} {
      reportErrorAndExit {Command does not remove collection specified as\
         filepath}
   }

   # get coresponding filename
   lassign [getCollectionFilename $coll] collfile colldesc

   if {![file exists $collfile]} {
      reportErrorAndExit "Collection $colldesc cannot be found"
   }

   # attempt to delete specified colletion
   if {[catch {
      file delete $collfile
   } errMsg ]} {
      reportErrorAndExit "Collection $colldesc cannot be removed.\n$errMsg"
   }
}

proc cmdModuleSaveshow {{coll default}} {
   reportDebug $coll

   # get coresponding filename
   lassign [getCollectionFilename $coll] collfile colldesc

   if {![file exists $collfile]} {
      reportErrorAndExit "Collection $colldesc cannot be found"
   }

   # read collection
   lassign [readCollectionContent $collfile $colldesc] coll_path_list\
      coll_mod_list coll_nuasked_list

   # collection should at least define a path or a mod
   if {[llength $coll_path_list] == 0 && [llength $coll_mod_list] == 0} {
      reportErrorAndExit "$colldesc is not a valid collection"
   }

   displaySeparatorLine
   report [sgr hi $collfile]:\n
   report [formatCollectionContent $coll_path_list $coll_mod_list\
      $coll_nuasked_list 1]
   displaySeparatorLine
}

proc cmdModuleSavelist {show_oneperline show_mtime} {
   # if a target is set, only list collection matching this
   # target (means having target as suffix in their name)
   set colltarget [get-env MODULES_COLLECTION_TARGET]
   if {$colltarget ne {}} {
      set suffix .$colltarget
      set targetdesc " (for target \"$colltarget\")"
   } else {
      set suffix {}
      set targetdesc {}
   }

   reportDebug "list collections for target \"$colltarget\""

   set coll_list [findCollections]

   if { [llength $coll_list] == 0} {
      report "No named collection$targetdesc."
   } else {
      set list {}
      if {$show_mtime} {
         displayTableHeader hi Collection 59 {Last mod.} 19
      }
      report "Named collection list$targetdesc:"
      set display_list {}
      set len_list {}
      set max_len 0
      if {$show_mtime || $show_oneperline} {
         set display_idx 0
         set one_per_line 1
      } else {
         set display_idx 1
         set one_per_line 0
      }

      foreach coll [lsort -dictionary $coll_list] {
         # remove target suffix from names to display
         regsub $suffix$ [file tail $coll] {} mod

         # no need to test mod consistency as findCollections does not return
         # collection whose name starts with "."
         if {$show_mtime} {
            set filetime [clock format [getFileMtime $coll]\
               -format {%Y/%m/%d %H:%M:%S}]
            lappend display_list [format %-60s%19s $mod $filetime]
         } else {
            lappend display_list $mod
            lappend len_list [set len [string length $mod]]
            if {$len > $max_len} {
               set max_len $len
            }
         }
      }

      displayElementList noheader {} {} $one_per_line $display_idx\
         $display_list $len_list $max_len
   }
}


proc cmdModuleSource {args} {
   reportDebug $args
   foreach fpath $args {
      set absfpath [getAbsolutePath $fpath]
      if {$fpath eq {}} {
         reportErrorAndExit {File name empty}
      } elseif {[file exists $absfpath]} {
         pushMode load
         # relax constraint of having a magic cookie at the start of the
         # modulefile to execute as sourced files may need more flexibility
         # as they may be managed outside of the modulefile environment like
         # the initialization modulerc file
         execute-modulefile $absfpath $absfpath $absfpath 0
         popMode
      } else {
         reportErrorAndExit "File $fpath does not exist"
      }
   }
}

proc cmdModuleUnsource {args} {
   reportDebug $args
   foreach fpath $args {
      set absfpath [getAbsolutePath $fpath]
      if {$fpath eq {}} {
         reportErrorAndExit {File name empty}
      } elseif {[file exists $absfpath]} {
         pushMode unload
         # relax constraint of having a magic cookie at the start of the
         # modulefile to execute as sourced files may need more flexibility
         # as they may be managed outside of the modulefile environment like
         # the initialization modulerc file
         execute-modulefile $absfpath $absfpath $absfpath 0
         popMode
      } else {
         reportErrorAndExit "File $fpath does not exist"
      }
   }
}

proc cmdModuleLoad {context uasked args} {
   reportDebug "loading $args (context=$context, uasked=$uasked)"

   set ret 0
   pushMode load
   foreach mod $args {
      # if a switch action is ongoing...
      if {$context eq {swload}} {
         set swprocessing 1
         # context is ReqLo if switch is called from a modulefile
         if {![isMsgRecordIdTop]} {
            set context reqlo
         }
      }

      # record evaluation attempt on specified module name
      registerModuleEvalAttempt $context $mod
      lassign [getPathToModule $mod] modfile modname
      if {$modfile eq {}} {
         set ret 1
         # go to next module to unload
         continue
      }

      if {[isModuleEvalFailed load $modname]} {
         reportDebug "$modname ($modfile) load was already tried and failed"
         # nullify this evaluation attempt to avoid duplicate issue report
         unregisterModuleEvalAttempt $context $mod
         continue
      }

      # if a switch action is ongoing...
      if {[info exists swprocessing]} {
         # pass the DepRe mod list to the calling cmdModuleSwitch procedure to
         # let it handle the load phase of the DepRe mechanism along with the
         # DepRe modules set from switched off module.
         upvar deprelist swdeprelist
         upvar isuasked isuasked

         # transmit loaded mod name for switch report summary
         uplevel 1 set new $modname
      }

      # set a unique id to record messages related to this evaluation.
      set msgrecid load-$modname-[getEvalModuleStackDepth]
      pushMsgRecordId $msgrecid

      # record evaluation attempt on actual module name
      registerModuleEvalAttempt $context $modname
      registerModuleEvalAttempt $context $modfile

      # check if passed modname correspond to an already loaded modfile
      # and get its loaded name (in case it has been loaded as full path)
      set loadedmodname [getLoadedMatchingName $modname]
      if {$loadedmodname ne {}} {
         set modname $loadedmodname
      }

      pushSettings
      if {[set errCode [catch {
         if {[isModuleLoaded $modname] || [isModuleLoading $modname]} {
            reportDebug "$modname ($modfile) already loaded/loading"
            # exit treatment but no need to restore settings
            continue
         }

         # register altname of modname prior any conflict check
         eval setLoadedAltname $modname [getAllModuleResolvedName $modname]

         if {[getAutoHandling]} {
            # get loaded modules holding a requirement on modname and able to
            # be reloaded
            set deprelist [getUnmetDependentLoadedModuleList $modname]
            reportDebug "depre mod list is '$deprelist'"

            # Reload all modules that have declared a prereq on mod as they
            # may take benefit from their prereq availability if it is newly
            # loaded. First perform unload phase of the reload, prior mod load
            # to ensure these dependent modules are unloaded with the same
            # loaded prereq as when they were loaded
            if {[llength $deprelist] > 0} {
               array set isuasked [reloadModuleListUnloadPhase deprelist\
                  [getForce] {Unload of dependent _MOD_ failed} depun]
               if {[info exists swprocessing]} {
                  set swdeprelist [expr {[info exists swdeprelist] ? [concat\
                     $deprelist $swdeprelist] : $deprelist}]
               }
            }
         }

         if {[execute-modulefile $modfile $modname $mod]} {
            break
         }

         # register this evaluation on the main one that triggered it (after
         # load evaluation to report correct order with other evaluations)
         registerModuleEval $context $modname

         # raise an error if a conflict violation is detected 
         # do that after modfile evaluation to give it the chance to solve its
         # (module unload) conflicts through its evaluation
         lassign [doesModuleConflict $modname] doescon modconlist\
            moddecconlist
         set retisconun [eval isModuleEvaluated conun $modconlist]
         if {![set retiseval [eval isModuleEvaluated any $modconlist]] ||\
            [currentMsgRecordId] ne [topMsgRecordId] || !$retisconun} {
            # more appropriate msg if an evaluation was attempted or is
            # by-passed. error is reported using declared conflict name (as if
            # it was raised raised from a conflict modulefile command)
            set conmsg [expr {$retiseval || [getForce] ? [getConIsLoadedMsg\
               $moddecconlist [is-loading $modconlist]] : [getErrConflictMsg\
               $modname $moddecconlist]}]
         }

         # still proceed if force mode enabled
         if {[getForce] && $doescon} {
            # report warning if not already done
            set report_con 1
            if {[info exists ::report_conflict($modname)]} {
               # check if conflict has not been already reported with an
               # alternative name
               foreach modalt [concat [getLoadedAltname $modconlist]\
                  $modconlist $moddecconlist] {
                  foreach reportmod $::report_conflict($modname) {
                     if {[doesModuleMatchesName $modalt $reportmod]} {
                        set report_con 0
                        break
                     }
                  }
               }
            }
            if {$report_con && [info exists conmsg]} {
               reportWarning $conmsg
            }
            # raise conun-specific msg to top level if attempted
            if {$retisconun} {
               reportWarning [getErrConUnMsg $moddecconlist] 1
            }
         } elseif {$doescon} {
            if {$retisconun} {
               if {[info exists conmsg]} {
                  reportError $conmsg
               }
               # raise conun-specific msg to top level if attempted
               error [getErrConUnMsg $moddecconlist]
            } else {
               set errlocalreport 1
               error $conmsg
            }
         }

         add-path append LOADEDMODULES $modname
         # allow duplicate modfile entries for virtual modules
         add-path append --duplicates _LMFILES_ $modfile
         # update cache arrays
         setLoadedModule $modname $modfile $uasked

         # register declared conflict in environment
         if {[set modcon [getLoadedConflict $modname 1]] ne {}} {
            add-path append MODULES_LMCONFLICT $modcon
         }

         # declare the prereq of this module
         if {[set modpre [getLoadedPrereq $modname 1]] ne {}} {
            add-path append MODULES_LMPREREQ $modpre
         }

         # declare module as not asked by user (automatically loaded as
         # dependency) if it is the case
         if {!$uasked} {
            add-path append MODULES_LMNOTUASKED $modname
         }

         # declare the alternative names of this module
         if {[set modalt [getLoadedAltname $modname 1]] ne {}} {
            add-path append MODULES_LMALTNAME $modalt
         }

         # Load phase of dependent module reloading. These modules can adapt
         # now that mod is seen loaded. Except if switch action ongoing (DepRe
         # load phase will occur from switch)
         if {[getAutoHandling] && [llength $deprelist] > 0 && ![info exists\
            swprocessing]} {
            reloadModuleListLoadPhase deprelist [array get isuasked]\
               [getForce] {Reload of dependent _MOD_ failed} depre
         }

         # report a summary of automated evaluations if no error
         reportModuleEval
      } errMsg]] != 0 && $errCode != 4} {
         if {$errMsg ne {}} {
            reportError $errMsg [expr {![info exists errlocalreport]}]
         }
         # report switched-on module load failure under switch info block
         # unless the above reportError call already put a mesg to this block
         if {[info exists swprocessing] && ($errMsg eq {} || [info exists\
            errlocalreport])} {
            # warn as this issue does not lead to a rollback of switch action
            reportWarning "Load of switched-on $modname failed" 1
         }
         # rollback settings if some evaluation went wrong
         set ret 1
         restoreSettings
         # remove from successfully evaluated module list
         registerModuleEval $context $modname 1 load
         unset -nocomplain errlocalreport
      }
      popSettings

      # report all recorded messages for this evaluation
      reportMsgRecord "Loading [sgr hi $modname]"
      popMsgRecordId
   }
   popMode

   return $ret
}

proc cmdModuleUnload {context match auto force onlyureq onlyndep args} {
   reportDebug "unloading $args (context=$context, match=$match, auto=$auto,\
      force=$force, onlyureq=$onlyureq, onlyndep=$onlyndep)"

   set ret 0
   pushMode unload
   foreach mod $args {
      # if a switch action is ongoing...
      if {$context eq {swunload}} {
         set swprocessing 1
         # context is ConUn if switch is called from a modulefile
         if {![isMsgRecordIdTop]} {
            set context conun
         }
      }

      # record evaluation attempt on specified module name
      registerModuleEvalAttempt $context $mod
      # resolve by also looking at matching loaded module
      lassign [getPathToModule $mod {} $match] modfile modname errkind
      if {$modfile eq {}} {
         # no error return if module is not loaded
         if {$errkind eq {notloaded}} {
            reportDebug "$modname is not loaded"
         } else {
            set ret 1
         }
         # go to next module to unload
         continue
      }

      if {$onlyureq && ![isModuleUnloadable $modname]}  {
         reportDebug "$modname ($modfile) is required by loaded module or\
            asked by user"
         continue
      }

      if {[isModuleEvalFailed unload $modname]} {
         reportDebug "$modname ($modfile) unload was already tried and failed"
         # nullify this evaluation attempt to avoid duplicate issue report
         unregisterModuleEvalAttempt $context $mod
         continue
      }

      # if a switch action is ongoing...
      if {[info exists swprocessing]} {
         # pass the DepRe mod list to the calling cmdModuleSwitch
         # procedure to let it handle the load phase of the DepRe
         # mechanism once the switched-to module will be loaded
         upvar deprelist deprelist
         upvar isuasked isuasked

         # transmit unloaded mod name for switch report summary
         uplevel 1 set old $modname
      }
      # set a unique id to record messages related to this evaluation.
      set msgrecid unload-$modname-[getEvalModuleStackDepth]
      pushMsgRecordId $msgrecid

      # record evaluation attempt on actual module name
      registerModuleEvalAttempt $context $modname
      registerModuleEvalAttempt $context $modfile

      pushSettings
      if {[set errCode [catch {
         # error if unloading module violates a registered prereq
         # and auto handling mode is disabled
         set prereq_list [getDependentLoadedModuleList $modname]
         if {[llength $prereq_list] > 0 && (![getAutoHandling] || !$auto)} {
            # force mode should not affect if we only look for mods w/o dep
            if {([getForce] || $force) && !$onlyndep} {
               # in case unload is called for a DepRe mechanism or a purge do
               # not warn about prereq violation enforced as it is due to the
               # dependent module which is already in a violation state
               if {$auto || !$force} {
                  reportWarning [getDepLoadedMsg $prereq_list]
               }
            } else {
               set errlocalreport 1
               # exit treatment but no need to set return code to error if
               # called from a 'module unload' command in a modulefile in a
               # load evaluation mode, as set conflict will raise error at end
               # of modulefile evaluation
               if {$onlyndep} {
                  set errharmless 1
               }
               error [expr {[eval isModuleEvaluated any $prereq_list] ?\
                  [getDepLoadedMsg $prereq_list] : [getErrPrereqMsg $modname\
                  $prereq_list 0]}]
            }
         }

         if {[getAutoHandling] && $auto} {
            # compute lists of modules to update due to modname unload prior
            # unload to get requirement info before it vanishes

            # DepUn: Dependent to Unload (modules actively requiring modname
            # or a module part of this DepUn batch)
            set depunnpolist [getDependentLoadedModuleList $modname 1 0 1 0]
            set depunlist [getDependentLoadedModuleList $modname 1 0 0 0]
            # look at both regular dependencies or No Particular Order
            # dependencies: use NPO result if situation can be healed with NPO
            # dependencies, which will be part of DepRe list to restore the
            # correct loading order for them
            if {[llength $depunnpolist] <= [llength $depunlist]} {
               set depunlist $depunnpolist
            }
            reportDebug "depun mod list is '$depunlist'"

            # do not check for UReqUn mods coming from DepUn modules as these
            # DepUn modules are reloaded
            set urequnqry [expr {[info exists swprocessing] ? $modname :\
               [concat $depunlist [list $modname]]}]

            # UReqUn: Useless Requirement to Unload (autoloaded requirements
            # of modname or DepUn modules not required by any remaining mods)
            set urequnlist [getUnloadableLoadedModuleList $urequnqry]
            reportDebug "urequn mod list is '$urequnlist'"

            # DepRe: Dependent to Reload (modules optionnaly dependent or in
            # conflict with modname, DepUn or UReqUn modules + modules
            # dependent of a module part of this DepRe batch)
            set deprelist [getDependentLoadedModuleList [concat $urequnlist\
               $depunlist [list $modname]] 0 0 1 0 1 1]
            reportDebug "depre mod list is '$deprelist'"

            # DepUn mods are merged into the DepRe list as an attempt to
            # reload these DepUn mods is made once switched-to mod loaded
            if {[info exists swprocessing]} {
               set deprelist [sortModulePerLoadedAndDepOrder [concat\
                  $depunlist $deprelist] 1]
               set depunlist {}
            }

            # Reload of all DepRe mods, as they may adapt from the mod unloads
            # happening here. First perform unload phase of the reload, prior
            # mod unloads to ensure these dependent mods are unloaded with the
            # same loaded prereq as when they were loaded. Avoid modules not
            # satisfying their constraint.
            if {[llength $deprelist] > 0} {
               array set isuasked [reloadModuleListUnloadPhase deprelist\
                  [getForce] {Unload of dependent _MOD_ failed} depun]
            }

            # DepUn modules unload prior main mod unload
            if {[llength $depunlist] > 0} {
               foreach unmod [lreverse $depunlist] {
                  if {[cmdModuleUnload depun match 0 0 0 0 $unmod]} {
                     # stop if one unload fails unless force mode enabled
                     set errMsg "Unload of dependent $unmod failed"
                     if {[getForce] || $force} {
                        reportWarning $errMsg 1
                     } else {
                        error $errMsg
                     }
                  }
               }
            }
         }

         # register this evaluation on the main one that triggered it (prior
         # unload evaluation to report correct order with other evaluations)
         registerModuleEval $context $modname

         if {[execute-modulefile $modfile $modname $mod]} {
            break
         }

         # get module position in loaded list to remove corresponding loaded
         # modulefile (entry at same position in _LMFILES_)
         # need the unfiltered loaded module list to get correct index
         set lmidx [lsearch -exact [getLoadedModuleList 0] $modname]
         unload-path LOADEDMODULES $modname
         unload-path --index _LMFILES_ $lmidx
         if {![isModuleUserAsked $modname]} {
            unload-path MODULES_LMNOTUASKED $modname
         }
         # update cache arrays
         unsetLoadedModule $modname $modfile

         # unregister declared conflict
         if {[set modcon [getLoadedConflict $modname 1]] ne {}} {
            unload-path MODULES_LMCONFLICT $modcon
         }
         unsetLoadedConflict $modname

         # unset prereq declared for this module
         if {[llength [set modpre [getLoadedPrereq $modname]]] > 0} {
            unload-path MODULES_LMPREREQ [getLoadedPrereq $modname 1]
         }
         unsetLoadedPrereq $modname

         # unset alternative names declared for this module
         if {[llength [set modalt [getLoadedAltname $modname]]] >0} {
            unload-path MODULES_LMALTNAME [getLoadedAltname $modname 1]
         }
         unsetLoadedAltname $modname

         if {[getAutoHandling] && $auto} {
            # UReqUn modules unload now DepUn+main mods are unloaded
            if {[llength $urequnlist] > 0} {
               set urequnlist [lreverse $urequnlist]
               for {set i 0} {$i < [llength $urequnlist]} {incr i 1} {
                  set unmod [lindex $urequnlist $i]
                  if {[cmdModuleUnload urequn match 0 0 0 0 $unmod]} {
                     # just warn if UReqUn module cannot be unloaded, main
                     # unload process continues, just the UReqUn modules that
                     # are required by unmod (whose unload failed) are
                     # withdrawn from UReqUn module list
                     reportWarning "Unload of useless requirement $unmod\
                        failed" 1
                     lassign [getDiffBetweenList $urequnlist\
                        [getRequiredLoadedModuleList $unmod]] urequnlist
                  }
               }
            }

            # DepRe modules load phase now DepUn+UReqUn+main mods are unloaded
            # except if a switch action is ongoing as this DepRe load phase
            # will occur after the new mod load
            if {[llength $deprelist] > 0 && ![info exists swprocessing]} {
               reloadModuleListLoadPhase deprelist [array get isuasked]\
                  [getForce] {Reload of dependent _MOD_ failed} depre
            }
         }

         # report a summary of automated evaluations if no error
         reportModuleEval
      } errMsg]] != 0 && $errCode != 4} {
         if {$errMsg ne {}} {
            reportError $errMsg [expr {![info exists errlocalreport]}]
         }
         # report switched-off module unload failure under switch info block
         # unless the above reportError call already put a mesg to this block
         if {[info exists swprocessing] && ($errMsg eq {} || [info exists\
            errlocalreport])} {
            reportError "Unload of switched-off $modname failed" 1
         }
         # rollback settings if some evaluation went wrong
         if {![info exists errharmless]} {
            set ret 1
            restoreSettings
            # remove from successfully evaluated module list
            registerModuleEval $context $modname 1 unload
         }
         unset -nocomplain errlocalreport errharmless
      }
      popSettings

      # report all recorded messages for this evaluation
      reportMsgRecord "Unloading [sgr hi $modname]"
      popMsgRecordId
   }
   popMode

   return $ret
}

proc cmdModulePurge {} {
   reportDebug called.

   # create a message record if for purge action to let underlying unload
   # actions to know they are not the top-level action
   pushMsgRecordId purge-[getEvalModuleStackDepth]

  # unload one by one to ensure same behavior whatever auto_handling state
   # force it to handle loaded modules in violation state
   eval cmdModuleUnload unload match 0 1 0 0 [lreverse [getLoadedModuleList]]

   # no sumup report for purge action for the moment
   popMsgRecordId
}

proc cmdModuleReload {args} {
   # reload all loaded modules if no module list passed
   set lmlist [expr {[llength $args] == 0 ? [getLoadedModuleList] : $args}]
   reportDebug "reloading $lmlist"

   # create a message record if for reload action to let underlying unload and
   # load actions to know they are not the top-level action
   pushMsgRecordId reload-[getEvalModuleStackDepth]

   # no reload of all loaded modules attempt if constraints are violated
   if {[llength $args] == 0 && ![areModuleConstraintsSatisfied]} {
      reportError {Cannot reload modules, some of their constraints are not\
         satistied}
   } else {
      pushSettings
      if {[set errCode [catch {
         # run unload then load-again phases
         array set isuasked [reloadModuleListUnloadPhase lmlist]
         reloadModuleListLoadPhase lmlist [array get isuasked]
      } errMsg]] == 1} {
         reportError $errMsg
         # rollback settings if some evaluation went wrong
         restoreSettings
      }
      popSettings
   }

   # report all recorded messages for this evaluation
   reportMsgRecord "Reloading all loaded modules"
   popMsgRecordId
}

proc cmdModuleAliases {} {
   # disable error reporting to avoid modulefile errors
   # to mix with avail results
   inhibitErrorReport

   # parse paths to fill g_moduleAlias and g_moduleVersion
   foreach dir [getModulePathList exiterronundef] {
      getModules $dir {} 0 {}
   }

   reenableErrorReport

   set display_list {}
   foreach name [lsort -dictionary [array names ::g_moduleAlias]] {
      lappend display_list "[sgr al $name] -> $::g_moduleAlias($name)"
   }
   displayElementList Aliases hi sepline 1 0 $display_list

   set display_list {}
   foreach name [lsort -dictionary [array names ::g_moduleVersion]] {
      lappend display_list "[sgr sy $name] -> $::g_moduleVersion($name)"
   }
   displayElementList Versions hi sepline 1 0 $display_list
}

proc cmdModuleAvail {show_oneperline show_mtime show_filter search_filter\
   args} {
   if {[llength $args] == 0} {
      lappend args *
   }

   if {$show_mtime || $show_oneperline} {
      set one_per_line 1
      set hstyle terse
      set theader_shown 0
      set theader_cols [list hi Package/Alias 39 Versions 19 {Last mod.} 19]
   } else {
      set one_per_line 0
      set hstyle sepline
   }

   # disable error reporting to avoid modulefile errors
   # to mix with avail results
   inhibitErrorReport

   foreach mod $args {
      # look if aliases have been defined in the global or user-specific
      # modulerc and display them if any in a dedicated list
      lassign [listModules {} $mod $show_mtime $show_filter [concat\
         $search_filter [list rc_alias_only]]] display_list len_list max_len
      if {[llength $display_list] > 0 && $show_mtime && !$theader_shown} {
         set theader_shown 1
         eval displayTableHeader $theader_cols
      }
      displayElementList {global/user modulerc} hi $hstyle $one_per_line 0\
         $display_list $len_list $max_len

      foreach dir [getModulePathList exiterronundef] {
         lassign [listModules $dir $mod $show_mtime $show_filter [concat\
            $search_filter [list wild]]] display_list len_list max_len
         if {[llength $display_list] > 0 && $show_mtime && !$theader_shown} {
            set theader_shown 1
            eval displayTableHeader $theader_cols
         }
         displayElementList $dir mp $hstyle $one_per_line 0 $display_list\
            $len_list $max_len
      }
   }

   reenableErrorReport
}

proc cmdModuleUse {args} {
   reportDebug $args

   if {$args eq {}} {
      showModulePath
   } else {
      set pos prepend
      foreach path $args {
         switch -- $path {
            -a - --append - -append {
               set pos append
            }
            -p - --prepend - -prepend {
               set pos prepend
            }
            {} {
               reportError {Directory name empty}
            }
            default {
               # tranform given path in an absolute path to avoid dependency
               # to the current work directory. except if this path starts
               # with a variable reference
               if {[string index $path 0] ne {$}} {
                  set path [getAbsolutePath $path]
               }
               if {[file isdirectory [resolvStringWithEnv $path]]} {
                  pushMode load
                  catch {
                     add-path $pos MODULEPATH $path
                  }
                  popMode
               } else {
                  reportError "Directory '$path' not found"
               }
            }
         }
      }
   }
}

proc cmdModuleUnuse {args} {
   reportDebug $args

   if {$args eq {}} {
      showModulePath
   } else {
      foreach path $args {
         # get current module path list
         # no absolute path conversion for the moment
         if {![info exists modpathlist]} {
            set modpathlist [getModulePathList returnempty 0 0]
         }

         # skip empty string
         if {$path eq {}} {
            reportError {Directory name empty}
            continue
         }

         # transform given path in an absolute path which should have been
         # registered in the MODULEPATH env var. however for compatibility
         # with previous behavior where relative paths were registered in
         # MODULEPATH given path is first checked against current path list
         set abspath [getAbsolutePath $path]
         if {[isInList $modpathlist $path]} {
            set unusepath $path
         } elseif {[isInList $modpathlist $abspath]} {
            set unusepath $abspath
         } else {
            set unusepath {}
         }

         if {$unusepath ne {}} {
            pushMode unload
            catch {
               unload-path MODULEPATH $unusepath
            }
            popMode

            # refresh path list after unload
            set modpathlist [getModulePathList returnempty 0 0]
            if {[isInList $modpathlist $unusepath]} {
               reportWarning "Did not unuse $unusepath"
            }
         }
      }
   }
}

proc cmdModuleAutoinit {} {
   reportDebug called.

   # flag to make renderSettings define the module command
   set ::g_autoInit 1

   # initialize env variables around module command
   pushMode load

   # default MODULESHOME
   setenv MODULESHOME @prefix@

   # register command location
   setenv MODULES_CMD [getAbsolutePath $::argv0]

   # define current Modules version if versioning enabled
   @VERSIONING@if {![info exists ::env(MODULE_VERSION)]} {
   @VERSIONING@   setenv MODULE_VERSION @MODULES_RELEASE@@MODULES_BUILD@
   @VERSIONING@   setenv MODULE_VERSION_STACK @MODULES_RELEASE@@MODULES_BUILD@
   @VERSIONING@}

   # initialize default MODULEPATH and LOADEDMODULES
   if {![info exists ::env(MODULEPATH)] || $::env(MODULEPATH) eq {}} {
      # set modpaths defined in .modulespath config file if it exists
      if {[file readable @initdir@/.modulespath]} {
         set fdata [split [readFile @initdir@/.modulespath] \n]
         foreach fline $fdata {
            if {[regexp {^\s*(.*?)\s*(#.*|)$} $fline match patharg] == 1\
               && $patharg ne {}} {
               eval cmdModuleUse --append [split $patharg :]
            }
         }
      }

      if {![info exists ::env(MODULEPATH)]} {
         setenv MODULEPATH {}
      }
   }
   if {![info exists ::env(LOADEDMODULES)]} {
      setenv LOADEDMODULES {}
   }

   # source initialization modulerc if any and if no env already initialized
   if {$::env(MODULEPATH) eq {} && $::env(LOADEDMODULES) eq {}\
      && [file exists @initdir@/modulerc]} {
      cmdModuleSource @initdir@/modulerc
   }

   popMode
}

proc cmdModuleInit {args} {
   set init_cmd [lindex $args 0]
   set init_list [lrange $args 1 end]
   set notdone 1
   set nomatch 1

   reportDebug $args

   # Define startup files for each shell
   set files(csh) [list .modules .cshrc .cshrc_variables .login]
   set files(tcsh) [list .modules .tcshrc .cshrc .cshrc_variables .login]
   set files(sh) [list .modules .bash_profile .bash_login .profile .bashrc]
   set files(bash) $files(sh)
   set files(ksh) $files(sh)
   set files(fish) [list .modules .config/fish/config.fish]
   set files(zsh) [list .modules .zshrc .zshenv .zlogin]

   # Process startup files for this shell
   set current_files $files($::g_shell)
   foreach filename $current_files {
      if {$notdone} {
         set filepath $::env(HOME)
         append filepath / $filename

         reportDebug "Looking at $filepath"
         if {[file readable $filepath] && [file isfile $filepath]} {
            set newinit {}
            set thismatch 0

            foreach curline [split [readFile $filepath] \n] {
               # Find module load/add command in startup file 
               set comments {}
               if {$notdone && [regexp {^([ \t]*module[ \t]+(load|add)[\
                  \t]*)(.*)} $curline match cmd subcmd modules]} {
                  set nomatch 0
                  set thismatch 1
                  regexp {([ \t]*\#.+)} $modules match comments
                  regsub {\#.+} $modules {} modules

                  # remove existing references to the named module from
                  # the list Change the module command line to reflect the 
                  # given command
                  switch -- $init_cmd {
                     list {
                        if {![info exists notheader]} {
                           report "$::g_shell initialization file\
                              \$HOME/$filename loads modules:"
                           set notheader 0
                        }
                        report \t$modules
                     }
                     add {
                        foreach newmodule $init_list {
                           set modules [replaceFromList $modules $newmodule]
                        }
                        lappend newinit "$cmd$modules $init_list$comments"
                        # delete new modules in potential next lines
                        set init_cmd rm
                     }
                     prepend {
                        foreach newmodule $init_list {
                           set modules [replaceFromList $modules $newmodule]
                        }
                        lappend newinit "$cmd$init_list $modules$comments"
                        # delete new modules in potential next lines
                        set init_cmd rm
                     }
                     rm {
                        set oldmodcount [llength $modules]
                        foreach oldmodule $init_list {
                           set modules [replaceFromList $modules $oldmodule]
                        }
                        set modcount [llength $modules]
                        lappend newinit [expr {$modcount > 0 ?\
                           "$cmd$modules$comments" : [string trim $cmd]}]
                        if {$oldmodcount > $modcount} {
                           set notdone 0
                        }
                     }
                     switch {
                        set oldmodule [lindex $init_list 0]
                        set newmodule [lindex $init_list 1]
                        set newmodules [replaceFromList $modules\
                           $oldmodule $newmodule]
                        lappend newinit $cmd$newmodules$comments
                        if {$modules ne $newmodules} {
                           set notdone 0
                        }
                     }
                     clear {
                        lappend newinit [string trim $cmd]
                     }
                  }
               } elseif {$curline ne {}} {
                  # copy the line from the old file to the new
                  lappend newinit $curline
               }
            }

            if {$init_cmd ne {list} && $thismatch} {
               reportDebug "Writing $filepath"
               if {[catch {
                  set fid [open $filepath w]
                  puts $fid [join $newinit \n]
                  close $fid
               } errMsg ]} {
                  reportErrorAndExit "Init file $filepath cannot be\
                     written.\n$errMsg"
               }
            }
         }
      }
   }

   # quit in error if command was not performed due to no match
   if {$nomatch && $init_cmd ne {list}} {
      reportErrorAndExit "Cannot find a 'module load' command in any of the\
         '$::g_shell' startup files"
   }
}

# provide access to modulefile specific commands from the command-line, making
# them standing as a module sub-command (see module procedure)
proc cmdModuleResurface {cmd args} {
   reportDebug "cmd='$cmd', args='$args'"

   pushMode load
   pushCommandName $cmd

   # run modulefile command and get its result
   if {[catch {eval $cmd $args} res]} {
      # report error if any and return false
      reportError $res
   } else {
      # register result depending of return kind (false or text)
      switch -- $cmd {
         module-info {
            set ::g_return_text $res
         }
         default {
            if {$res == 0} {
               # render false if command returned false
               set ::g_return_false 1
            }
         }
      }
   }

   popCommandName
   popMode
}

proc cmdModuleTest {args} {
   reportDebug "testing $args"

   pushMode test
   set first_report 1
   foreach mod $args {
      lassign [getPathToModule $mod] modfile modname
      if {$modfile ne {}} {
         # only one separator lines between 2 modules
         if {$first_report} {
            displaySeparatorLine
            set first_report 0
         }
         report "Module Specific Test for [sgr hi $modfile]:\n"
         execute-modulefile $modfile $modname $mod
         displaySeparatorLine
      }
   }
   popMode
}

proc cmdModuleClear {{doit {}}} {
   reportDebug "($doit)"
   # fetch confirmation if no arg passed and force mode disabled
   if {$doit eq {} && ![getForce]} {
      # ask for it if stdin is attached to a terminal
      if {![catch {fconfigure stdin -mode}]} {
         report "Are you sure you want to clear all loaded modules!? \[n\] " 1
         flush $::reportfd
      }
      # fetch stdin content even if not attached to terminal in case some
      # content has been piped to this channel
      set doit [gets stdin]
   }

   # should be confirmed or forced to proceed
   if {[string equal -nocase -length 1 $doit y] || [getForce]} {
      set vartoclear [list LOADEDMODULES MODULES_LMALTNAME MODULES_LMCONFLICT\
         MODULES_LMNOTUASKED MODULES_LMPREREQ _LMFILES_]

      # add any reference counter variable to the list to unset
      set vartoclear [concat $vartoclear [array names ::env -glob *_modshare]\
         [array names ::env -glob MODULES_MODSHARE_*]]

      # unset all Modules runtime variables
      pushMode load
      foreach var $vartoclear {
         unset-env $var
      }
      popMode
   } else {
      reportInfo "Modules runtime information were not cleared"
   }
}

proc cmdModuleConfig {dump_state args} {
   # parse arguments
   set nameunset 0
   switch -- [llength $args] {
      1 {
         lassign $args name
      }
      2 {
         lassign $args name value
         # check if configuration should be set or unset
         if {$name eq {--reset}} {
            set name $value
            set nameunset 1
            unset value
         }
      }
   }

   reportDebug "dump_state='$dump_state', reset=$nameunset,\
      name=[expr {[info exists name] ? "'$name'" : {<undef>}}], value=[expr\
      {[info exists value] ? "'$value'" : {<undef>}}]"

   array set confvar [list contact MODULECONTACT auto_handling\
      MODULES_AUTO_HANDLING avail_indepth MODULES_AVAIL_INDEPTH\
      collection_pin_version MODULES_COLLECTION_PIN_VERSION collection_target\
      MODULES_COLLECTION_TARGET color MODULES_COLOR colors MODULES_COLORS\
      pager MODULES_PAGER rcfile MODULERCFILE run_quarantine\
      MODULES_RUN_QUARANTINE silent_shell_debug MODULES_SILENT_SHELL_DEBUG\
      term_background MODULES_TERM_BACKGROUND]

   array set confvalid [list auto_handling [list 0 1] avail_indepth [list 0\
      1] collection_pin_version [list 0 1] color [list never auto always]\
      silent_shell_debug [list 0 1] term_background [list dark light]]

   # define each attribute/fetched value pair
   array set confval [list contact [getContact] auto_handling\
      [getAutoHandling] avail_indepth [getAvailInDepth] avail_report_dir_sym\
      $::flag_default_dir avail_report_mfile_sym $::flag_default_mf\
      collection_pin_version [pinVersionInCollection] collection_target\
      [get-env $confvar(collection_target) <undef>] color [getColor] colors\
      $::g_colors_list ignored_dirs [getIgnoredDirs] pager "$::g_pager\
      $::g_pager_opts" rcfile [get-env $confvar(rcfile) <undef>]\
      run_quarantine [get-env $confvar(run_quarantine) <undef>]\
      silent_shell_debug [get-env $confvar(silent_shell_debug) <undef>]\
      siteconfig $::g_siteconfig tcl_ext_lib $::g_tclextlib term_background\
      [getTermBackground]]

   # catch any environment variable set for modulecmd run-time execution
   foreach runenvvar [array names ::env -glob MODULES_RUNENV_*] {
      set runenvconf [string tolower [string range $runenvvar 8 end]]
      set confval($runenvconf) [get-env $runenvvar]
      # enable modification of runenv conf
      set confvar($runenvconf) $runenvvar
   }

   if {[info exists name] && ![info exists confval($name)]} {
      reportErrorAndExit "Configuration key '$name' does not exist"
   # set configuration
   } elseif {[info exists name] && ($nameunset || [info exists value])} {
      if {![info exists confvar($name)]} {
         reportErrorAndExit "Configuration key '$name' cannot be altered"
      } elseif {$nameunset} {
         # unset configuration variable
         pushMode load
         unsetenv $confvar($name)
         popMode
      } elseif {[info exists confvalid($name)] && [notInList\
         $confvalid($name) $value]} {
         reportErrorAndExit "Valid values for configuration key '$name' are:\
            $confvalid($name)"
      } else {
         # effectively set configuration variable
         pushMode load
         setenv $confvar($name) $value
         popMode
      }
   # report configuration
   } else {
      # some configuration may be overridden from the command-line
      array set confasked [list auto_handling asked_auto_handling color\
         asked_color]
      # internal conf value may be map to a public value
      array set confvtrans [list color [list 0 never 1 auto 2 always]]

      reportVersion
      reportSeparateNextContent
      displayTableHeader hi {Config. name} 24 {Value (set by if default\
         overridden)} 54

      # report all configs or just queried one
      if {[info exists name]} {
         set varlist [list $name]
      } else {
         set varlist [lsort [array names confval]]
      }

      foreach var $varlist {
         set valrep [displayConfig $confval($var)\
            [expr {[info exists confvar($var)] ? $confvar($var) : {}}]\
            [expr {[info exists confasked($var)] ? $confasked($var) : {}}]\
            [expr {[info exists confvtrans($var)] ? $confvtrans($var) : {}}]]
         append displist [format {%-25s %s} $var $valrep] \n
      }
      report $displist 1
      reportSeparateNextContent

      if {$dump_state} {
         displayTableHeader hi {State name} 24 {Value} 54
         # define each attribute/fetched state value pair
         set state_list [list\
            cmdline "$::argv0 $::argv"\
            debug $::g_debug\
            force [getForce]\
            is_stderr_tty [isStderrTty]\
            is_win [isWin]\
            machine [uname machine]\
            os "[uname sysname] [uname release]"\
            pager_started $::start_pager\
            paginate $::use_pager\
            path_separator [getPathSeparator]\
            rc_loaded [expr {[info exists ::g_rc_loaded] ? $::g_rc_loaded :\
               {<undef>}}]\
            siteconfig_loaded [info exists ::g_siteconfig_loaded]\
            shell $::g_shell\
            shelltype $::g_shellType\
            subcmd $::command\
            subcmd_args $::otherargv\
            tcl_ext_lib_loaded [info exists ::g_tclextlib_loaded]\
            tcl_version [info patchlevel]\
            term_columns [getTtyColumns]]

         unset displist
         foreach {var val} $state_list {
            append displist [format {%-25s %s} $var $val] \n
         }
         report $displist 1
         reportSeparateNextContent

         # report environment variable set related to Modules
         displayTableHeader hi {Env. variable} 24 {Value} 54
         set envvar_list {}
         foreach var [list LOADEDMODULES _LMFILES_ MODULE* *_modshare\
            *_modquar *_module*] {
            set envvar_list [concat $envvar_list [array names ::env -glob\
               $var]]
         }
         unset displist
         foreach var [lsort -unique $envvar_list] {
            append displist [format {%-25s %s} $var $::env($var)] \n
         }
         report $displist 1
      }
   }
}

proc cmdModuleHelp {args} {
   pushMode help
   set first_report 1
   foreach arg $args {
      lassign [getPathToModule $arg] modfile modname

      if {$modfile ne {}} {
         # only one separator lines between 2 modules
         if {$first_report} {
            displaySeparatorLine
            set first_report 0
         }
         report "Module Specific Help for [sgr hi $modfile]:\n"
         execute-modulefile $modfile $modname $arg
         displaySeparatorLine
      }
   }
   popMode
   if {[llength $args] == 0} {
      reportVersion
      report {Usage: module [options] [command] [args ...]

Loading / Unloading commands:
  add | load      modulefile [...]  Load modulefile(s)
  rm | unload     modulefile [...]  Remove modulefile(s)
  purge                             Unload all loaded modulefiles
  reload | refresh                  Unload then load all loaded modulefiles
  switch | swap   [mod1] mod2       Unload mod1 and load mod2

Listing / Searching commands:
  list            [-t|-l]           List loaded modules
  avail   [-d|-L] [-t|-l] [--indepth|--no-indepth] [mod ...]
                                    List all or matching available modules
  aliases                           List all module aliases
  whatis          [modulefile ...]  Print whatis information of modulefile(s)
  apropos | keyword | search  str   Search all name and whatis containing str
  is-loaded       [modulefile ...]  Test if any of the modulefile(s) are loaded
  is-avail        modulefile [...]  Is any of the modulefile(s) available
  info-loaded     modulefile        Get full name of matching loaded module(s)

Collection of modules handling commands:
  save            [collection|file] Save current module list to collection
  restore         [collection|file] Restore module list from collection or file
  saverm          [collection]      Remove saved collection
  saveshow        [collection|file] Display information about collection
  savelist        [-t|-l]           List all saved collections
  is-saved        [collection ...]  Test if any of the collection(s) exists

Shell's initialization files handling commands:
  initlist                          List all modules loaded from init file
  initadd         modulefile [...]  Add modulefile to shell init file
  initrm          modulefile [...]  Remove modulefile from shell init file
  initprepend     modulefile [...]  Add to beginning of list in init file
  initswitch      mod1 mod2         Switch mod1 with mod2 from init file
  initclear                         Clear all modulefiles from init file

Environment direct handling commands:
  prepend-path [-d c] var val [...] Prepend value to environment variable
  append-path [-d c] var val [...]  Append value to environment variable
  remove-path [-d c] var val [...]  Remove value from environment variable

Other commands:
  help            [modulefile ...]  Print this or modulefile(s) help info
  display | show  modulefile [...]  Display information about modulefile(s)
  test            [modulefile ...]  Test modulefile(s)
  use     [-a|-p] dir [...]         Add dir(s) to MODULEPATH variable
  unuse           dir [...]         Remove dir(s) from MODULEPATH variable
  is-used         [dir ...]         Is any of the dir(s) enabled in MODULEPATH
  path            modulefile        Print modulefile path
  paths           modulefile        Print path of matching available modules
  clear           [-f]              Reset Modules-specific runtime information
  source          scriptfile [...]  Execute scriptfile(s)
  config [--dump-state|name [val]]  Display or set Modules configuration

Switches:
  -t | --terse    Display output in terse format
  -l | --long     Display output in long format
  -d | --default  Only show default versions available
  -L | --latest   Only show latest versions available
  -a | --append   Append directory to MODULEPATH
  -p | --prepend  Prepend directory to MODULEPATH
  --auto          Enable automated module handling mode
  --no-auto       Disable automated module handling mode
  -f | --force    By-pass dependency consistency or confirmation dialog

Options:
  -h | --help     This usage info
  -V | --version  Module version
  -D | --debug    Enable debug messages
  --paginate      Pipe mesg output into a pager if stream attached to terminal
  --no-pager      Do not pipe message output into a pager
  --color[=WHEN]  Colorize the output; WHEN can be 'always' (default if
                  omitted), 'auto' or 'never'}
   }
}

########################################################################
# main program

# needed on a gentoo system. Shouldn't hurt since it is
# supposed to be the default behavior
fconfigure stderr -translation auto

if {[catch {
   # parse all command-line arguments before doing any action, no output is
   # made during argument parse to wait for potential paging to be setup
   set show_help 0
   set show_version 0
   reportDebug "CALLING $argv0 $argv"

   # Load extension library if enabled
   @libtclenvmodules@if {[file readable $g_tclextlib]} {
   @libtclenvmodules@   reportDebug "Load Tcl extension library ($g_tclextlib)"
   @libtclenvmodules@   load $g_tclextlib Envmodules
   @libtclenvmodules@   set g_tclextlib_loaded 1
   @libtclenvmodules@}
   # use fallback procs if extension library is not loaded
   if {[info commands readFile] eq {}} {
      rename ::__readFile ::readFile
      rename ::__getFilesInDirectory ::getFilesInDirectory
   }

   # source site configuration script if any
   sourceSiteConfig

   # Parse shell
   set g_shell [lindex $argv 0]
   switch -- $g_shell {
      sh - bash - ksh - zsh {
         set g_shellType sh
      }
      csh - tcsh {
         set g_shellType csh
      }
      fish - cmd - tcl - perl - python - ruby - lisp - cmake - r {
         set g_shellType $g_shell
      }
      default {
         reportErrorAndExit "Unknown shell type \'($g_shell)\'"
      }
   }

   # extract options and command switches from other args
   set otherargv {}
   set extraargv {}
   set ddelimarg 0
   # split first arg if multi-word string detected for compat with previous
   # doc on module usage with scripting language: module('load mod1 mod2')
   set argtoparse [if {[llength [lindex $argv 1]] > 1} {concat [split [lindex\
      $argv 1]] [lrange $argv 2 end]} {lrange $argv 1 end}]
   foreach arg $argtoparse {
      if {[info exists ignore_next_arg]} {
         unset ignore_next_arg
      } else {
         switch -glob -- $arg {
            -D - --debug {
               set g_debug 1
            }
            --help - -h {
               set show_help 1
            }
            -V - --version {
               set show_version 1
            }
            --paginate {
               set asked_pager 1
            }
            --no-pager {
               set asked_pager 0
            }
            --auto {
               set asked_auto_handling 1
            }
            --no-auto {
               set asked_auto_handling 0
            }
            -f - --force {
               set asked_force 1
            }
            --color* {
               switch -- [string range $arg 8 end] {
                  always - {} {
                     set asked_color 2
                  }
                  auto {
                     set asked_color 1
                  }
                  never {
                     set asked_color 0
                  }
               }
            }
            -t - --terse - -l - --long - --default - -L - --latest {
               # command-specific switches that can for compatibility be
               # passed before the command name, so add them to a specific
               # arg list to ensure command name as first position argument
               lappend extraargv $arg
            }
            -d {
               # in case of *-path command, -d means --delim
               if {$ddelimarg} {
                  lappend otherargv $arg
               } else {
                  lappend extraargv $arg
               }
            }
            -a - --append - -append - -p - --prepend - -prepend - --delim -\
            -delim - --delim=* - -delim=* - --duplicates - --index -\
            --notuasked - --indepth - --no-indepth - --dump-state - --reset {
               # command-specific switches interpreted later on
               lappend otherargv $arg
            }
            append-path - prepend-path - remove-path {
               # detect *-path commands to say -d means --delim, not --default
               set ddelimarg 1
               lappend otherargv $arg
            }
            --human - -v - --verbose - -s - --silent - -c - --create - -i -\
            --icase - --userlvl=* {
               # ignore C-version specific option, no error only warning
               reportWarning "Unsupported option '$arg'"
            }
            -u - --userlvl {
               reportWarning "Unsupported option '$arg'"
               # also ignore argument value
               set ignore_next_arg 1
            }
            -* {
                reportErrorAndExit "Invalid option '$arg'\nTry\
                  'module --help' for more information."
            }
            default {
               lappend otherargv $arg
            }
         }
      }
   }

   set command [lindex $otherargv 0]
   set otherargv [concat [lreplace $otherargv 0 0] $extraargv]

   # now options are known initialize error report (start pager if enabled)
   initErrorReport

   # put back quarantine variables in env, if quarantine mechanism supported
   @quarantinesupport@if {[info exists env(MODULES_RUN_QUARANTINE)] && $g_shellType ne {csh}} {
   @quarantinesupport@   foreach var [split $env(MODULES_RUN_QUARANTINE)] {
   @quarantinesupport@      # check variable name is valid
   @quarantinesupport@      if {[regexp {^[A-Za-z_][A-Za-z0-9_]*$} $var]} {
   @quarantinesupport@         set quarvar ${var}_modquar
   @quarantinesupport@         # put back value
   @quarantinesupport@         if {[info exists env($quarvar)]} {
   @quarantinesupport@            reportDebug "Release '$var' environment variable from\
                  quarantine ($env($quarvar))"
   @quarantinesupport@            set env($var) $env($quarvar)
   @quarantinesupport@            unset env($quarvar)
   @quarantinesupport@         # or unset env var if no value found in quarantine
   @quarantinesupport@         } elseif {[info exists env($var)]} {
   @quarantinesupport@            reportDebug "Unset '$var' environment variable after\
                  quarantine"
   @quarantinesupport@            unset env($var)
   @quarantinesupport@         }
   @quarantinesupport@      } elseif {[string length $var] > 0} {
   @quarantinesupport@         reportWarning "Bad variable name set in MODULES_RUN_QUARANTINE\
               ($var)"
   @quarantinesupport@      }
   @quarantinesupport@   }
   @quarantinesupport@}

   if {$show_help} {
      cmdModuleHelp
      cleanupAndExit 0
   }
   if {$show_version} {
      reportVersion
      cleanupAndExit 0
   }

   # no modulefile is currently being interpreted
   pushModuleFile {}

   # eval needed to pass otherargv as list to module proc
   eval module "{$command}" $otherargv
} errMsg ]} {
   # no use of reportError here to get independent from any
   # previous error report inhibition
   report "[sgr er ERROR]: $errMsg"
   # init error report here in case the error raised before the regular init
   initErrorReport
   cleanupAndExit 1
}

cleanupAndExit 0

# ;;; Local Variables: ***
# ;;; mode:tcl ***
# ;;; End: ***
# vim:set tabstop=3 shiftwidth=3 expandtab autoindent: