preg_match(): No ending delimiter '^' found [duplicate]

Answer 1

You must add delimiters to your regex:

if (preg_match('/' . $mail_pat . '/', $email, $components)) {

$mail_pat starts with a ^ but ends with another character, which causes the error since there are no matching delimiters.

Answer 2

Perl based regex should be inside the delimeters.. "/your regex here/".. the deprecated POSIX regex were the one which did not require any delimeter.. eg ereg(")