#!/usr/bin/perl -w

use strict;

use English;

my $user=shift;
my ($name, $uid, $gid, $home, $shell);

if ($user!~/^\d+$/) {
    ($name,$uid,$gid,$home,$shell)=(getpwnam($user))[0,2,3,7,8];
} else {
    ($name,$uid,$gid,$home,$shell)=(getpwuid($user))[0,2,3,7,8];
}

if (!defined($name) or !defined($uid) or !defined($gid)) {
    die "Failed to get passwd entry for $user: $!\n";
}

$GID = $EGID = "$gid $gid";

$UID = $EUID = $uid;

my $term=undef;
$term=$ENV{'TERM'} if (defined($ENV{'TERM'}));

%ENV=(
    'USER'     => $name,
    'USERNAME' => $name,
    'LOGNAME'  => $name,
    'HOME'     => $home,
    'SHELL'    => $shell,
    'PATH'     => '/bin:/usr/bin:/usr/local/bin',
);

$ENV{'TERM'}=$term if (defined($term));

exec @ARGV or die "exec failed: $!";