Check url format using php not work

Question

When $url_xxx = www.googlecom or http://www.5555testetstcom or http://wwwgooglecom it's will echo OK WHY ?

<?PHP
$url_xxx = mysqli_real_escape_string($db_mysqli,$_POST['url_xxx']);
if(!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$url_xxx))
{
    echo "URL incorrect format";
}
else
{
    echo "OK";
}
?>

Because your regex is invalid? Why would you be checking for `[-a-z0-9+&@#\/%=~_|]` in a host? — Devon Bessemer, Dec 01 '16 at 16:32
How about using parse_url `http://php.net/manual/en/function.parse-url.php` to check the parts of the url. Then check only the parts with regex if needed. — JustOnUnderMillions, Dec 01 '16 at 16:32

score 0 · Answer 1 · edited May 23 '17 at 12:01

Your Regex is badly shaped. You can decompose it in three parts;

\b(?:(?:https?|ftp)://|www.) (Starts with http or https or such)
[-a-z0-9+&@#/%?=~_|!:,.;]* (Any character)
[-a-z0-9+&@#/%=~_|] (Any character)

Your expression reads "Anything starting with {1}, followed by {2} that can appear from 0 to many times, followed by {3} (which is anything)"

So, well, as {2} is optional due the * modifier, it finally reads like "Anything starting with http:// and followed by anything matches

First I would recommend using Rubular to check your Regex when you build them, it's a REALLY helpful website http://rubular.com . If you would want to fix the regex you should at least require some dots in the middle.

Second, for this particular case you should check this response by Gordon in Best way to check if a URL is valid

Which snipped from there the response is:

if (filter_var($url, FILTER_VALIDATE_URL) === FALSE) {
    die('Not a valid URL');
}

Still echo Yes on this string. Why ? `` – arectiyu rokiyw Dec 02 '16 at 01:52 — arectiyu rokiyw, Dec 02 '16 at 01:52

Check url format using php not work

1 Answers1