#!/usr/bin/perl

# The LearningOnline Network with CAPA
# Scott Harrison
# YEAR=2001
# 8/15

# A CGI script that dynamically outputs a barcode.

# I'm using format=Code39.
# The valid formats are
# EAN13, EAN8, UPCA, UPCE, NW7, Code39,
# ITF, IATA2of5, Matrix2of5, and COOP2of5.

# Example usage: /cgi-bin/barcode.gif?encode=12345*31*MSUL1

use strict;
use GD::Barcode::Code39;

map {
    my ($name, $value) = split(/=/,$_);
    $value =~ tr/+/ /;
    $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
    if ($name eq 'encode') {
	$ENV{'form.'.$name}=$value;
    }
} (split(/&/,$ENV{'QUERY_STRING'}));

# Tell the server we are sending a gif graphic
print <<END;
Content-type: image/gif

END

unless(defined($ENV{'form.encode'}) and length($ENV{'form.encode'})) {
    $ENV{'form.encode'}='***ERROR***UNDEFINED***';
}

my $oGdBar=GD::Barcode::Code39->new($ENV{'form.encode'});
if ($GD::Barcode::errStr or !defined($oGdBar)) {
    warn($GD::Barcode::errStr);
    $oGdBar=GD::Barcode::Code39->new('***ERROR***INVALID***');
}
my $bindata=$oGdBar->plot->png; # create barcode image
undef $oGdBar;
binmode(STDOUT);
open OUT,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into gif image
print OUT $bindata; # output image
$|=1; # be sure to flush before closing
close OUT;