#!/usr/bin/perl -T

# include standard library modules
use 5.004;
use strict;

# declare public constants

# declare const string constants

my $const = {};

$const->{author}    = 'Gerald Charles Wagner';
$const->{data}      = '.css';
$const->{filename}  = 'public';
$const->{mime}      = 'text/css';
$const->{regex}		= '\-\.0-9A-Z_a-z';
$const->{release}   = 'May 2000';
$const->{style}     = '';
$const->{version}   = '2.0';

my $constStyle = {
    Macintosh       => 'MAC',
};

# declare public variables

# declare param client/server variables

my $param = {};

# declare subroutines

# access: execute MAIN procedure
# source: GET QUERY_STRING and POST CONTENT_LENGTH
# target: true/false
MAIN: {
    local *SOURCE;

	$param->{script} = $ENV{SCRIPT_NAME};
	$param->{script} =~ s{^.*/(.*)$}{$1}ox;
	$param->{script} =~ m{^([$const->{regex}]+)$}o;
	$param->{script} = $1;

    # parse QUERY_STRING variable into filename, options, login, and file structure

    ($param->{filename}, $param->{options}) = split (/\+/, $ENV{QUERY_STRING});
    $param->{filename} = $const->{filename}
        unless (length ($param->{filename}));
	$param->{filename} =~ m{^([$const->{regex}]+)$}o;
	$param->{filename} = $1;

    # update the client browser with the platform-specific stylesheet

	print ("Content-type: $const->{mime}\n\n");

    USER: foreach (%{$constStyle}) {
        if ($ENV{HTTP_USER_AGENT} =~ m{$_}) {
            $param->{base} = $constStyle->{$_};
			last USER;
        }
    }
    $param->{base} = ''
        unless (-e "$const->{style}$param->{filename}$param->{script}$param->{base}$const->{data}");

    open (SOURCE, "<$const->{style}$param->{filename}$param->{script}$param->{base}$const->{data}");
    while (<SOURCE>) {
        print;
    }
    close (SOURCE);
}
exit (0);