Decimal to Hex Converter

This was one of my own hand-crafted projects, it's pretty bad (doesn't do any error checking for erroneous input), but it works like it should :) and it even shows you the handy math involved :

Edit: I forgot to point it out the first time this is a Decimal to Hex RGB Converter, the only people I showed it to before, were told it was a RGB Converter, sorry.

Edit 2: Again I apologise for not using printf, sprintf, or pack, but when I coded this (Feb 2001) I had only even touched perl for a month or two at most.

#!/usr/bin/perl -w

use CGI;

use CGI::Carp "fatalsToBrowser";

use strict;

my %map = (0 => '0', 1 => 1, 2 => 2, 3 => 3, 4 => 4, 5 => 5, 6 => 6, 7
+ => 7, 8 => 8, 9 => 9, 10 => 'A', 11 => 'B', 12 => 'C', 13 => 'D', 14
+ => 'E', 15 => 'F');

my (@dtrip, @conv, @conv2, @conv3, @conv4);
my $cgi = new CGI;

print $cgi->header();

unless ($cgi->param('doit')) {
        print<<EOT;
<html>
<head>
<title>Decimal to Hex Converter</title>
</head>
<body bgcolor="black" text="white">
<center>
<h1>Decimal to Hex Converter</h1>
</center>
<p>Please enter the decimal triplet, eg: 44,26,127<BR>
<form action="hex.cgi" method="post">
<p><input type="text" name="doit" ><br>
<input type="submit" value="Convert">
</form>
</body>
</html>
EOT

} else {
if($cgi->param('doit')) {
        my $triplet = $cgi->param('doit');
        my $converted = &convert($triplet);

        print<<EOT;
<html>
<head>
<title>Decimal to Hex Converter</title>
<body bgcolor="black" text="white">
<center>
<h1>Decimal to Hex Converter</h1>
</center>
<center>
<h3>Converting @dtrip</h3>
</center>
<center>
<table cellpadding=10>
       
        <tr>
                <td>Converting $dtrip[0]</td>
                <td>Converting $dtrip[1]</td>
                <td>Converting $dtrip[2]</td>
        </tr>
        <tr>
EOT

$conv[0] = int($dtrip[0]/16);
$conv[1] = int($dtrip[1]/16);
$conv[2] = int($dtrip[2]/16);
print "\t\t" . '<td>' . "$dtrip[0] / 16 = $conv[0]" . '</td>' . "\n";
print "\t\t" . '<td>' . "$dtrip[1] / 16 = $conv[1]" . '</td>' . "\n";
print "\t\t" . '<td>' . "$dtrip[2] / 16 = $conv[2]" . '</td>' . "\n";
print<<EOT;
        </tr>
        <tr>
EOT

$conv2[0] = $conv[0] * 16;
$conv2[1] = $conv[1] * 16;
$conv2[2] = $conv[2] * 16;
print "\t\t" . '<td>' . "$conv[0] * 16 = $conv2[0]" . '</td>' . "\n";
print "\t\t" . '<td>' . "$conv[1] * 16 = $conv2[1]" . '</td>' . "\n";
print "\t\t" . '<td>' . "$conv[2] * 16 = $conv2[2]" . '</td>' . "\n";
print<<EOT;
        </tr>
        <tr>
EOT

$conv3[0] = $dtrip[0] - $conv2[0];
$conv3[1] = $dtrip[1] - $conv2[1];
$conv3[2] = $dtrip[2] - $conv2[2];
print "\t\t" . '<td>' . "$dtrip[0] - $conv2[0] = $conv3[0]" . '</td>' 
+. "\n";
print "\t\t" . '<td>' . "$dtrip[1] - $conv2[1] = $conv3[1]" . '</td>' 
+. "\n";
print "\t\t" . '<td>' . "$dtrip[2] - $conv2[2] = $conv3[2]" . '</td>' 
+. "\n";
print<<EOT;
        </tr>
        <tr>
EOT

$conv4[0] = $map{$conv[0]};
$conv4[1] = $map{$conv3[0]};
$conv4[2] = $map{$conv[1]};
$conv4[3] = $map{$conv3[1]};
$conv4[4] = $map{$conv[2]};
$conv4[5] = $map{$conv3[2]};
print "\t\t" . '<td>' . "$conv[0] and $conv3[0] = \n $conv4[0]$conv4[1
+]" . '</td>' . "\n";
print "\t\t" . '<td>' . "$conv[1] and $conv3[1] = \n $conv4[2]$conv4[3
+]" . '</td>' . "\n";
print "\t\t" . '<td>' . "$conv[2] and $conv3[2] = \n $conv4[4]$conv4[5
+]" . '</td>' . "\n";
print<<EOT;
        </tr></table>
        <center><h3>Final Hex is:
EOT
for(my $i=0;$i<=6; $i++) {
        print "$conv4[$i]";
}
print<<EOT;
</h3></center>
</body>
</html>
EOT
}
}

sub convert {
        my $triplet = $_[0];
        my $converted;

        @dtrip = split(/\,/, $triplet);

        for(my $i=1; $i<4; $i++) {
        my $j = $i - 1;

        my $first = int($dtrip[$j] / 16);
        my $temp = $first * 16;
        my $second = $dtrip[$j]-$temp;
        my $hex1 = $map{$first};
        my $hex2 = $map{$second};
        $converted .= "$hex1$hex2";
    }
        return $converted;
}
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