Entry

How do I validate an Email Address using PHP3?

Jul 25th, 2005 04:04
J. Amgine Neilson, mike gifford,

The basic answer is to compare the e-mail address using a regular
expression, returning a boolean true if the e-mail address follows the
basic RFC requirements or a boolean false if it does not. The preg_match
function of PHP has been available since PHP 3.0.9
Here's a fairly strict regular expression which can be used:
$pattern = '/
            ^           # anchor at the beginning
            [^@\s]+     # name is all characters, except @ and whitespace
            @           # the @ divides the name and domain
            (
             [-a-z0-9]+ # (sub)domains are letters, numbers, and hyphens
             \.         # separated by a dot
            )+          # and there can be one or more of them
            (
             [a-z]{2}   # top level domain can be a 2-letter alpha
country code
             |com|net   # or one of
             |edu|org   # many
             |gov|mil   # possible
             |int|biz   # 3 letter
             |pro       # or
             |info|arpa # more
             |aero|coop # ICANN
             |name      # tlds - and more options
             |museum    # might be added
            )
            $           # anchor at the end
           /ix          # everything is case-insensitive
';
Here is the complete function:
/**
 * Function: validate_email
 * ***
 * Purpose: to perform basic e-mail address validation.
 *   Be aware this regx is not perfect, and it is possible to fool it.
 * From: PHP cookbook
 * ***
 * @param string $address text e-mail address
 * @return bool FALSE = not valid e-mail address
 * *** */
function validate_email ($address='') {
	$pattern =
'/^[^@\s]+@([-a-z0-9]+\.)+([a-z]{2}|com|net|edu|org|gov|mil|int|biz|pro|info|arpa|aero|coop|name|museum)$/ix';
	return preg_match ($pattern, $address);
}