How to minify JS or CSS on the fly [closed]

After a lot of searching and sites optimizations i really recommend to use this script for CSS files:

<style>
<?php
     $cssFiles = array(
      "style.css",
      "style2.css"
    );

    $buffer = "";
    foreach ($cssFiles as $cssFile) {
      $buffer .= file_get_contents($cssFile);
    }
    $buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);
    $buffer = str_replace(': ', ':', $buffer);
    $buffer = str_replace(array("\r\n", "\r", "\n", "\t", '  ', '    ', '    '), '', $buffer);
    echo($buffer);
?>
</style>

It compress all css files into one and past it into html, reducing the number of additional requests to zero. You can also make your own compressed.css file if you prefer this than pasting styles into html.