#!/usr/bin/perl

use CGI qw(:standard);

my $debug = 0;

my $q = new CGI;

my $cgi_user = $q->param('user');
my $cgi_pass = $q->param('pass');

# normally, you'd read this stuff from a user database file or DBM.
# to make this a single file example, tho, we'll read from the special
# DATA handle.  man perldata for more info.
# open USERS, "users.txt" or die "opening USERS: $!";

print
  "Content-type: text/plain\n\n",
  "cgi_user=\"$cgi_user\"\n",
  "cgi_pass=\"$cgi_pass\"\n"
    if $debug;

my $found = 0;
my $password = undef;
while (<DATA>) 
{
  chomp;
  my ($user, $pass) = split /:/;
  print qq[  "$user" => "$pass"\n] if $debug;
  if ($user eq $cgi_user)
  {
    $found = 1;
    $password = $pass;
    last;
  }
}

# close USERS or die "closing USERS: $!";

my $status;
my $good = 0;

if (not $found)
{
  $status = "unknown user \"$cgi_user\"";
  $good = 0;
}
elsif ($password ne $cgi_pass)
{
  $status = "known user \"$cgi_user\", bad password";
  $good = 0;
}
else 
{
  $status = "known user \"$cgi_user\", correct password";
  $good = 1;
}

print 
  header(),
  start_html("Tkil's CheckPass Sample CGI"),
  h1("Tkil's CheckPass Sample CGI"),
  start_form,
  "user", textfield('user'), br,
  "pass", textfield('pass'), br,
  "status: $status", br,
  "good: $good (", ($good ? "good" : "bad"), ")", br,
  submit,
  end_form,
  end_html;

# provide an error code if so desired
exit ($good ? 0 : 1);

__END__
tkil:xyzzy
bob:nothing
jim:secret