Preg_match для сайтов

        // Convert user input social URLs to username values
        $facebookUrl = $user->facebook;
        preg_match("/https?:\/\/(www\.)?facebook\.com\/([^\/]*)/", $facebookUrl, $matches);
        if ($matches){
            $user->facebook = $matches[2];
        }
        $twitterUrl = $user->twitter;
        preg_match("/https?:\/\/(www\.)?twitter\.com\/(#!\/)?@?([^\/]*)/", $twitterUrl, $matches);
        if ($matches){
            $user->twitter = $matches[3];
        }
        $linkedinUrl = $user->linkedin;
        preg_match("/https?:\/\/(www\.)?linkedin\.com\/in\/([^\/]*)/", $linkedinUrl, $matches);
        if ($matches){
            $user->linkedin = $matches[2];
        }
        $googleplusUrl = $user->googleplus;
        preg_match("/https?:\/\/plus\.google\.com\/([^\/]*)/", $googleplusUrl, $matches);
        if ($matches){
            $user->googleplus = $matches[1];
        }
        $pinterestUrl = $user->pinterest;
        preg_match("/https?:\/\/(www\.)?pinterest\.com\/([^\/]*)/", $pinterestUrl, $matches);
        if ($matches){
            $user->pinterest = $matches[2];
        }

'~^https://vk\\.com/(id\\d+|username)/?$~iu'

'~^https://instagram\\.com/username/?$~iu'

'~^http://my\\.mail\\.ru/mail/username/?$~iu'

'~^http://ok\\.ru/(?:profile/\\d+|username)/?$~iu'

'~^http://ask\\.fm/(?:id\\d+|username)/?$~iu'