[PHP] pobierz, plaintext 
   /*
    * It checks if string is an URL.
    *
    * @param string $string
    * @param string $flags
         * Posibility flags:
         * HOST_REQUIRED - URL with a host (example: http://url.com),
         * PATH_REQUIRED - URL with path after a name of domain (example: http://url.com/Home)
         * QUERY_REQUIRED - URL with a Query String (example: http://url.com/index.php?x=y).
    * @return boolean
    */
 function isURL($string, $flags='QUERY_REQUIRED') {
        if($flags=='HOST_REQUIRED') {
            return (bool)preg_match("/^(http|https|ftp|file):\/\/(www)?[a-zA-Z0-9_\/.\-]+\.[a-zA-Z0-9]+(\/)?$/i", $string);
        }
        else if($flags=='PATH_REQUIRED') {
            return (bool)preg_match("/^(http|https|ftp|file):\/\/(www)?[a-zA-Z0-9_\/.\-]+\.[a-zA-Z0-9]+\/[a-zA-Z0-9_.\-#]*$/i", $string);
        }
        else if($flags=='QUERY_REQUIRED') {
            return (bool)preg_match("/^(http|https|ftp|file):\/\/(www)?[a-zA-Z0-9_\/.\-]+\.[a-zA-Z0-9]+\/[a-zA-Z0-9_.\-#]*\?[a-zA-Z0-9_.,\-?#=&]+$/i", $string);
        }
[PHP] pobierz, plaintext