On-the-fly CSS Compression

style.css.php

<?php

/**
 * On-the-fly CSS Compression
 * Copyright (c) 2009 and onwards, Manas Tungare.
 * Creative Commons Attribution, Share-Alike.
 *
 * In order to minimize the number and size of HTTP requests for CSS content,
 * this script combines multiple CSS files into a single file and compresses
 * it on-the-fly.
 *
 * To use this in your HTML, link to it in the usual way:
 * <link rel="stylesheet" type="text/css" media="screen, print, projection" href="/css/compressed.css.php" />
 */
	
$files = array(
	"base.core.css",
	"base.layout.css",
	"base.menu.css"
);

/**
 * Ideally, you wouldn't need to change any code beyond this point.
 */
$buffer = '';

foreach ( $files as $file )
	$buffer .= @file_get_contents( $file );

// Remove comments
$buffer = preg_replace( '!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer );

// Remove space after colons
$buffer = str_replace(': ', ':', $buffer);

// Remove whitespace
$buffer = str_replace( array( "\r\n", "\r", "\n", "\t" ), '', $buffer );

// Collapse adjacent spaces into a single space
//$buffer = ereg_replace(" {2,}", ' ',$buffer);

// Remove spaces that might still be left where we know they aren't needed
$buffer = preg_replace( "/\s*([\{\}>~:;,])\s*/", "$1", $buffer );

// Remove last semi-colon in a block
$buffer = preg_replace( "/;\}/", "}", $buffer );

// Shorten HEX Color Codes (#666666 to #666)
$buffer = preg_replace( "/#([0-9a-fA-F])\\1([0-9a-fA-F])\\2([0-9a-fA-F])\\3/", "#$1$2$3", $buffer );

// Enable GZip encoding.
ob_start( "ob_gzhandler" );

// Enable caching
header( 'Cache-Control: public' );

// Expire in 7 days
header( 'Expires: ' . gmdate('D, d M Y H:i:s', time() + 604800) . ' GMT' );

// Set the correct MIME type, because Apache won't set it for us
header( 'Content-type: text/css' );

// Write everything out
echo( $buffer );