Validate an Email

gistfile1.aw

<?php
/**
 * Check an email address for correct format.
 *
 * @link  http://www.iamcal.com/publish/articles/php/parsing_email/
 * @link  http://www.w3.org/Protocols/rfc822/
 *
 * @param   string   email address
 * @param   boolean  strict RFC compatibility
 * @return  boolean
 */
function email($email, $strict = FALSE) {
    if ($strict === TRUE) {
        $qtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
        $dtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
        $atom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
        $pair = '\\x5c[\\x00-\\x7f]';

        $domain_literal = "\\x5b($dtext|$pair)*\\x5d";
        $quoted_string = "\\x22($qtext|$pair)*\\x22";
        $sub_domain = "($atom|$domain_literal)";
        $word = "($atom|$quoted_string)";
        $domain = "$sub_domain(\\x2e$sub_domain)*";
        $local_part = "$word(\\x2e$word)*";

        $expression = "/^$local_part\\x40$domain$/D";
    } else {
        $expression = '/^[-_a-z0-9\'+*$^&%=~!?{}]++(?:\.[-_a-z0-9\'+*$^&%=~!?{}]+)*+@(?:(?![-.])[-a-z0-9.]+(?<![-.])\.[a-z]{2,6}|\d{1,3}(?:\.\d{1,3}){3})(?::\d++)?$/iD';
    }

    return (bool) preg_match($expression, (string) $email);
}

?>