#!/usr/bin/perl -w
#
# userinit: utility to run user commands on startup
#

$MIN_USER_ID = 500;
$USER_INIT_FILE = ".userinit";
$verbose = 1;

use FileHandle;

my $fin = new FileHandle("</etc/passwd") or die "Could not open /etc/passwd: $!";

while(<$fin>) {

	my($user,undef,$uid,$gid,undef,$home,$shell) = split /:/;
	if($uid < $MIN_USER_ID) {
		next;
	}
	if(-f "$home/$USER_INIT_FILE") {
		my(undef,undef,undef,undef,$f_uid,$f_gid,undef) = stat("$home/$USER_INIT_FILE");

		#
		# Conduct some general paranoia checks.
		#
		if($f_uid != $uid) {
			if($verbose) { print STDERR "File not owned by user: $user" }
			next;
		}
		if($f_gid != $gid) {
			if($verbose) { print STDERR "File not owned by $user\'s group" }
			next;
		}

		#
		# Execute the command under a login shell, piped to mail
		#
		system("/bin/su - $user -c \"source $home/$USER_INIT_FILE | mail $user -s 'userinit output'\"");

	}
}

$fin->close();