posix-ere

This question already has an answer here: How can I convert ereg expressions to preg in PHP? 4 answers I'm sorry to ask a question but I am useless when it comes to understanding regex code. In a php module that I didn't write is the following function function isURL($url = NULL) { if($url==NULL) return false; $protocol = '(http://|https://)'; $allowed = '([a-z0-9]([-a-z0-9]*[a-z0-9]+)?)'; $regex = "^". $protocol . // must include the protocol '(' . $allowed . '{1,63}\.)+'. // 1 or several sub domains with a max of 63 chars '[a-z]' . '{2,6}'; // followed by a TLD if(eregi($regex, $url)==true)

Possible Duplicate: How can I convert ereg expressions to preg in PHP? I need help, below is a small VERY basic regex to somewhat validate an email, I do realize it does not work the greatest but for my needs it is ok for now. It currently uses PHP's eregi function which php.net says is now a depreciated function and I should use preg_match instead, simply replacing erei with preg_match does not work, can someone show me how to make it work? function validate_email($email) { if (!eregi("^[[:alnum:]][a-z0-9_.-]*@[a-z0-9.-]+\.[a-z]{2,4}$", $email)) { echo 'bad email'; } else { echo 'good email';