#!/usr/bin/perl -w
use strict;
use IO::File;
use Fcntl qw(:flock);

die "$0: bad usage\n" unless @ARGV==1 && $ARGV[0] !~ m/^-/;
my $username = shift @ARGV;
$username = $ENV{'USERV_USER'} if $username eq 'SELF';

sub result {
    print "@_\n" or die $!;
    exit 0;
}

my @pwent = getpwnam($username);
result 4, "no such user" unless @pwent;

my $encrpw= $pwent[1];
result 5, "password disabled" unless length $encrpw >= 13;

$!=0; my $pw = <STDIN>;
chomp $pw or die "reading password: $!\n";

my $lockpath = "/var/run/checkpasswd.synch";
my $lockf = new IO::File $lockpath, "w+" or die "open $lockpath: $!\n";
flock($lockf, LOCK_EX) or die "lock $lockpath: $!\n";
select(undef,undef,undef,0.5);
close $lockf;

my $crval = crypt($pw,$encrpw);

result 2, "incorrect password" unless  $crval eq $encrpw;

result 0, "ok";