#!/usr/bin/bin/perl -w
#
# resetenv.pl  v1.0
#
#       (C)1998 University of Minnesota, Department of Computer Science
#
#       Authors:  Mark A. Bentley <bentlema@cs.umn.edu>
#                 Kent Mein <mein@cs.umn.edu>
#                 Scott M. Dier <sdier@cs.umn.edu>
#
#       Description:  resetenv is a simple perl script to restore a set of
#       default dotfiles to users home directory.  The dotfiles are stored
#       in a ~template account, and when resetenv is envoked, it copies
#       those dotfiles, as specified in the resetenv.conf, to the user's 
#       home directory (who executed resetenv), saving the old dotfiles to 
#       a unique directory. The user should use .resetenvrc for their
#       configuration options.
#
#       A sample resetenv.conf is as follows:
#
#          .aliases            N   600
#          .cshrc              Y   600
#          .fvwm2rc            Y   600
#          .login              Y   600
#          .logout             Y   600
#          .xinitrc            Y   755
#          README.dotfiles     Y   600
#          .mailcap            N   600
#          .mime.types         N   600
#
#       The first field is the filename to move into the users home directory
#       when resetenv is envoked.  The second field is the "replace me?" field.
#       This is a "Y" (Yes)or "N" (No) answering the question of weather to 
#       replace a particular dotfile that already exists in the users home
#       directory.  This is most useful to the user who creates their own
#       config file (~/.resetenv) so that they have direct control over which
#       dotfiles are replaced with defaults, and which ones are not touched.
#       The third field is the permissions to apply to a newly copied dotfile.
#
################################################################################
#
# Modifications History:
#
# 10/30/1998 -- PATH is now set in case user's PATH doesn't have needed commands
#            -- Now root can't run me
# 08/04/2009 -- Works with directories now
#
################################################################################
#
# Configuration 
#
#
# This is the directory where old dotfiles will be saved

use Sys::Hostname;

$backupdir = "old-dotfiles";

# This is the path that is set so that the commands that resetenv uses
# (such as cp and mv) can be found even if the users PATH is foobared.

$ENV{PATH} = '/opt/gnu/bin:/opt/local/bin:/usr/bin:/bin';
print "PATH = ", $ENV{PATH}, "\n";

# find ~template
#
# Currently the default dotfiles are in a homedir.  They can be located
# anywhere that is convenient really, however we use a cross-mounted home
# directory for ease of maintenance.  Perhaps it might be nice to have
# different sets of dotfiles for different clusters, but this works 
# fine for now. --Mark
#
# Note:  getpw functions return ($name, $passwd, $uid, $gid, $quota, 
#        $comment, $gcos, $homedir, $shell)

@template = getpwnam("template");
$templatedir = $template[7];
unless ( -d $templatedir) { die "Can't find templatedir $templatedir: $!";}
print "Template dotfiles location: $templatedir\n\n";

unless ( -f "$templatedir/resetenv.conf" ) {
   die "$templatedir/resetenv.conf does not exist: $!";
} 

$configfile = "$templatedir/resetenv.conf";

# Find the homedir of the user
#
# Notes:  $< is a special variable for the UID of the user running
#         this process.

($name, $tmp, $uid, $gid, $tmp, $tmp, $gcos, $userdir, $tmp) = getpwuid($<);

print "Username:  $name      UID: $uid      GID: $gid\n";
print "    Name:  $gcos      Homedir:  $userdir\n\n";

if ( $name eq "root" ) {
   print "Idiot!  Don't run resetenv as root!  Bailing out!\n\n";
   exit;
}

if (!($userdir =~ /\/home\/(.*)/)) {
        print "resetenv can not be run on an account that has a " .
                "homedir that is not in /home\n";
        exit;
}

#
# Make a subdirectory in the user's home dir to keep old dotfiles
#

if ( ! -d "$userdir/$backupdir" ) {
   print "Creating $userdir/$backupdir\n";
   mkdir ("$userdir/$backupdir",477) or die "mkdir: $!\n";
}

($tmp,$tmp,$tmp,$dd,$mm,$yy,$tmp,$tmp,$tmp) = localtime(time);

#
# Create a directory to store old dotfiles
#

#$oldfilesdir = "$userdir/$backupdir/$mm-$dd-$yy";
my $mmddyyyy = sprintf '%02d-%02d-%04d', $mm + 1, $dd, $yy + 1900;
$oldfilesdir = "$userdir/$backupdir/$mmddyyyy";

$x=1;
$foo = "$oldfilesdir-$x";
while (-d $foo ) {
   $x++;
   $foo = "$oldfilesdir-$x";
}
$oldfilesdir = "$oldfilesdir-$x";
print "Creating $oldfilesdir\n\n";
mkdir ("$oldfilesdir",477);

#
# Determine which config file to use
#

if ( -f "$userdir/.resetenvrc" ) {
   $configfile = "$userdir/.resetenvrc";
}

#
# okay, now do the actual copying and such...
#

print "Using config file:  $configfile\n\n";

# added Wed, 19 Dec 2001 17:02:16 -0600
#  -sdier

open  LOG, ">$oldfilesdir/log";
print LOG "#resetenv log, ".`date`."#ran by euid:egid:uid:gid:ppid:host\n$>:$):$<:$(:".getppid().":".hostname()."\n";
close LOG;

open ( CONF, "$configfile" );
while ( <CONF> ) {
   ( $dotfile, $replace, $mode ) = split;
   print "$dotfile:  ";

   # if the file exists in the default directory
   if ((-f "$templatedir/$dotfile")||(-d "$templatedir/$dotfile")){

	   if (( -e "$userdir/$dotfile" ) && ( "$replace" eq "N" )) {
		   print "keeping current.\n";
	   } elsif ( -e "$userdir/$dotfile") {
		   print "installing default.\n";
		   system ("mv -f $userdir/$dotfile $oldfilesdir/$dotfile");
		   system ("cp -r $templatedir/$dotfile $userdir/$dotfile");
		   system ("chmod $mode $userdir/$dotfile");
	   } else {
		   system ("cp -r $templatedir/$dotfile $userdir/$dotfile");
		   system ("chmod $mode $userdir/$dotfile");
	   }

   } else { 

	   if (($dotfile ne ".") && ($dotfile ne "..")){
		   print "\nAlert! $dotfile not found in $templatedir\n\n"; 
	   }
   }
}
close ( CONF );

print "\nYour old dotfiles can be found in:\n\t$oldfilesdir\n";