<?php // minify_css.php - rev 20100220_0100
// A PHP script to clean comments and whitespace from css files

if ($argc !== 2) { // Exit with usage message if wrong number of parameters passed.
  exit ("minify_css.php cleans comments and whitespace from css files.\n" .
    "  Usage: php minify_css.php file.css\n");
}
$contents = file_get_contents ($argv[1]);
if ($contents === FALSE) { // Exit with error message if unable to read file.
  exit ("Error: Unable to read file: {$argv[1]}\n");
}
$optimize = TRUE;

  if ($optimize) {
    // Perform some safe CSS optimizations.
    $contents = str_replace("\r", '', $contents);  // Strip any and all carriage returns.
    // Match and process strings, comments and everything else, one chunk at a time.
    // To understand this regex, read: "Mastering Regular Expressions 3rd Edition" chapter 6.
    $contents = preg_replace_callback('%
      # One-regex-to-rule-them-all! - version: 20100220_0100
      # Group 1: Match a double quoted string.
      ("[^"\\\\]*+(?:\\\\.[^"\\\\]*+)*+") |  # or...
      # Group 2: Match a single quoted string.
      (\'[^\'\\\\]*+(?:\\\\.[^\'\\\\]*+)*+\') |  # or...
      # Group 3: Match a regular non-MacIE5-hack comment.
      (/\*[^\\\\*]*+\*++(?:[^\\\\*/][^\\\\*]*+\*++)*+/) |  # or...
      # Group 4: Match a MacIE5-type1 comment.
      (/\*(?:[^*\\\\]*+\**+(?!/))*+\\\\[^*]*+\*++(?:[^*/][^*]*+\*++)*+/(?<!\\\\\*/)) |  # or...
      # Group 5: Match a MacIE5-type2 comment.
      (/\*[^*]*\*+(?:[^/*][^*]*\*+)*/(?<=\\\\\*/))  # folllowed by...
      # Group 6: Match everything up to final closing regular comment
      ([^/]*+(?:(?!\*)/[^/]*+)*?)
      # Group 7: Match final closing regular comment
      (/\*[^/]++(?:(?<!\*)/(?!\*)[^/]*+)*+/(?<=(?<!\\\\)\*/)) |  # or...
      # Group 8: Match regular non-string, non-comment text.
      ([^"\'/]*+(?:(?!/\*)/[^"\'/]*+)*+)
      %Ssx', '_minify_css', $contents); // Do it!
    $contents = preg_replace('/^\s++/', '', $contents);             // Strip leading whitespace.
    $contents = preg_replace('/[ \t]*+\n\s*+/S', "\n", $contents);  // Consolidate multi-lines space.
    $contents = preg_replace('/(?<!\s)\s*+$/S', "\n", $contents);   // Ensure file ends in newline.
  }
/**
 * preg_replace_callback function to consolidate CSS code
 *
 * This is the callback function for the preg_replace_callback() used in
 * drupal_load_stylesheet_content(). Support for comment hacks is implemented here.
 */
function _minify_css($matches) {
  if ($matches[1]) {      // Group 1: Double quoted string.
    return $matches[1];   // Return the string unmodified.
  }
  elseif ($matches[2]) {  // Group 2: Single quoted string.
    return $matches[2];   // Return the string unmodified.
  }
  elseif ($matches[3]) {  // Group 3: Regular non-MacIE5-hack comment.
    return "\n";            // Return single space.
  }
  elseif ($matches[4]) {  // Group 4: MacIE5-hack-type-1 comment.
    return "\n/*\\T1*/\n";  // Return minimal MacIE5-hack-type-1 comment.
  }
  elseif ($matches[5]) {  // Group 5,6,7: MacIE5-hack-type-2 comment
    $matches[6] = preg_replace('/\s++([+>{};,)])/S', '$1', $matches[6]);  // Clean pre-punctuation.
    $matches[6] = preg_replace('/([+>{}:;,(])\s++/S', '$1', $matches[6]); // Clean post-punctuation.
    $matches[6] = preg_replace('/;?\}/S', "}\n", $matches[6]);            // Add a touch of formatting.
    return "\n/*T2\\*/" . $matches[6] . "\n/*T2E*/\n"; // Minify and reassemble composite type2 comment.
  }
  elseif (isset($matches[8])) { // Group 8: Non-string, non-comment. Safe to clean whitespace here.
    $matches[8] = preg_replace('/^\s++/', '', $matches[8]);               // Strip all leading whitespace.
    $matches[8] = preg_replace('/\s++$/', '', $matches[8]);               // Strip all trailing whitespace.
    $matches[8] = preg_replace('/\s{2,}+/', ' ', $matches[8]);            // Consolidate multiple whitespace.
    $matches[8] = preg_replace('/\s++([+>{};,)])/S', '$1', $matches[8]);  // Clean pre-punctuation.
    $matches[8] = preg_replace('/([+>{}:;,(])\s++/S', '$1', $matches[8]); // Clean post-punctuation.
    $matches[8] = preg_replace('/;?\}/S', "}\n", $matches[8]);            // Add a touch of formatting.
    return $matches[8];
  }
  return $matches[0] . "\n/* ERROR! Unexpected _proccess_css_minify() parameter */\n"; // never get here
}

// Write minified css to new file appending "_min" to the filename.
$outputfilename = preg_replace('/(.*)(\.[^.]+)/', '$1_min$2', $argv[1]);
file_put_contents($outputfilename, $contents);
?>