Concatenate or minify CSS and JS using php

php-css-js-concat-minify.php

<?php

/**
 * @return none
 */
function prepareView()
{
    compressFiles([
        'css/src/normalize.css',
        'css/src/styles.css',
    ], 'css/main.css');
    compressFiles([
        'js/src/jquery-1.8.1.min.js',
        'js/src/map-assets.js',
        'js/src/map-init.js',
        'js/src/map-functions.js',
        'js/src/map-route-lines.js',
        'js/src/map-library.js',
        'js/src/ui-functions.js',
    ], 'js/main.js');
}

/** Compress CSS */
function compressFiles($filePaths, $writeToPath)
{
    $string = '';
    foreach ($filePaths as $file) {
        $string .= file_get_contents($file);
    }
    if (STATUS == 'production') {
        $string = minify($string);
    } else {
        $string = concatenate($string);
    }

    file_put_contents($writeToPath, $string);
};

/**
 * @param string $string Text
 * @return mixed
 */
function minify($string)
{
    //http://stackoverflow.com/questions/19509863/how-to-remove-js-comments-using-php
    $pattern = '/(?:(?:\/\*(?:[^*]|(?:\*+[^*\/]))*\*+\/)|(?:(?<!\:|\\\|\'|\")\/\/.*))/';
    /* remove comments */
    $string = preg_replace($pattern, '', $string);
    /* remove tabs, spaces, new lines */
    $string = preg_replace('/\t+|\0+|\n+|\r+/', '', $string);
    /* remove blank spaces */
    $string = str_replace(['  ', '   ', '    '], '', $string);
    return $string;
}

/**
 * @param string $string Text
 * @return mixed
 */
function concatenate($string)
{
    //http://stackoverflow.com/questions/19509863/how-to-remove-js-comments-using-php
    $pattern = '/(?:(?:\/\*(?:[^*]|(?:\*+[^*\/]))*\*+\/)|(?:(?<!\:|\\\|\'|\")\/\/.*))/';
    return $string;
}