PHP code to verify url, email and ip

function is_valid_url($url){
 $p1 ='/(http|https|ftp)://[a-z0-9-]+(.[a-z0-9-]+)*(:[0-9]+)?(/.*)?$/i';
 return preg_match($p1, $url);
}

function is_valid_email($email){
 if (filter_var($email, FILTER_VALIDATE_EMAIL))
 return true;
 else
 return false;
}

function is_valid_ip($ip){
 if (filter_var($ip, FILTER_VALIDATE_IP))
 return true;
 else
 return false;
}

?>

email, url, PHP