How to get email address from a long string

Question

Building on mandaleeka's answer, break the string up using a space delimeter then use filter_var to sanitize then validate to see if what remains is a legitimate email address:

function extract_email_address ($string) {
    foreach(preg_split('/\s/', $string) as $token) {
        $email = filter_var(filter_var($token, FILTER_SANITIZE_EMAIL), FILTER_VALIDATE_EMAIL);
        if ($email !== false) {
            $emails[] = $email;
        }
    }
    return $emails;
}

If you're not sure which part of the space-separated string is the e-mail address, you can split the string by spaces and use

filter_var($email, FILTER_VALIDATE_EMAIL)

on each substring.

based from constantine regex.. works with ip address domain too.

$pattern="/(?:[A-Za-z0-9!#$%&'*+=?^_`{|}~-]+(?:\.[A-Za-z0-9!#$%&'*+=?^_`{|}~-]+)*|\"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*\")@(?:(?:[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?\.)+[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[A-Za-z0-9-]*[A-Za-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])/";

//$pattern="/[A-Za-z0-9_-]+@[A-Za-z0-9_-]+\.([A-Za-z0-9_-][A-Za-z0-9_]+)/";

$subject="Hello [email protected] francis a@b words [email protected] words 2 words123 [email protected]";


preg_match_all($pattern, $subject, $matches);

Updating @Rob Locken's answers:

function extract_email_address ($string) {
   $emails = array();
   $string = str_replace("\r\n",' ',$string);
   $string = str_replace("\n",' ',$string);

   foreach(preg_split('/ /', $string) as $token) {
        $email = filter_var($token, FILTER_VALIDATE_EMAIL);
        if ($email !== false) { 
            $emails[] = $email;
        }
    }
    return $emails;
}

This small PHP script will help us to extract the email address from a long paragraph or text. Just copy paste this script and save it as a PHP file (extract.php):

$string="[email protected] MIME-Version: bla bla bla";

$pattern="/(?:[a-z0-9!#$%&'*+=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+=?^_`{|}~-]+)*|\"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])/";

preg_match_all($pattern, $string, $matches);

foreach($matches[0] as $email){
    echo $email.", ";
}
?>

The above script will produce this result:

[email protected],

Email addresses are really tricky to filter using regular expressions because there are so many possible allowable characters. It can be done, but you may have to tweak it some to get exactly what you need.

You could start with something like this:

$string = "[email protected] MIME-Version: bla bla bla";
$matches = array();
$pattern = '/[A-Za-z0-9_-]+@[A-Za-z0-9_-]+\.([A-Za-z0-9_-][A-Za-z0-9_]+)/'
preg_match($pattern,$string,$matches);

And then $matches should contain your email address.