#!/usr/bin/perl -w
# this script outputs a gif 
# set color, width, and height
use strict;

$|++;

binmode STDOUT;

print "Content-Type: image/gif\n\n";
print gif_file "FF0000", 0x33, 0x10;

######################################
sub gif_file{
    my ($hexrgb, $wid, $hgh) = @_;

    my %c;
    @c{qw(r g b)} = map hex, unpack "A2"x3, $hexrgb;

    return pack "C*", (
        0x47, 0x49, 0x46, 0x38, 0x37,  0x61,  $wid,  0x00,
        $hgh, 0x00, 0xA1, 0x01, 0x00, $c{r}, $c{g}, $c{b},
        0xFF, 0xFF, 0xFF, 0x00, 0x00,  0x00,  0x00,  0x00,
        0x00, 0x21, 0xF9, 0x04, 0x05,  0x00,  0x00,  0x01,
        0x00, 0x2C, 0x00, 0x00, 0x00,  0x00,  $wid,  0x00,
        $hgh, 0x00, 0x40, 0x02, $hgh,  0x84,  0x8F,  0xA9,
        0xCB, 0xED, 0x0F, 0xA3, 0x9C,  0xB4,  0xDA,  0x8B,
        0xB3, 0xDE, 0x9C, 0x17, 0x00,  0x3B,
    );
}