Get file absolute path from file URL in PHP Reading several questions regarding the topic, I made my function to return file's absolute path from the file URL. As I'm using this in an WordPress environment, hence I availed untrailingslashit() in it.

/**
 * Get file absolute path from URL.
 *
 * @author  carlosveucv
 * @link    https://stackoverflow.com/a/17744219/1743124
 * 
 * @param   string $file_url File URL.
 * @return  string           File path.
 * --------------------------------------------------------------------------
 */
function wp20171021_get_file_path_from_url( $file_url ) {
    $file_path = parse_url( $file_url, PHP_URL_PATH );
    return wp_normalize_path( $_SERVER['DOCUMENT_ROOT'] . $file_path );
}



How bulletproof is this?
What kind of caveats this might have in real world?
I tested this in Windows, so is it 'cross platform-friendly?
This should be the most cross platform way and uses less memory (also doesn't depend on wp)

function get_file_path_from_url( $file_url ){
   return realpath($_SERVER['DOCUMENT_ROOT'] . parse_url( $file_url, PHP_URL_PATH ));
}


It uses the native PHP function realpath().