Test if a remote url exists with PHP and CURL

If you have to test if a local file exists you will probably use the php file_exists function, but if you have to test a remote file, that is to say a remote url, than you can use CURL and get the headers returned by the http request. If you receive a 200 code, than it’s ok, else the url is not correct.

This function is included in the Mini Bots Class.

function url_exists($url) {
	$ch = @curl_init($url);
	@curl_setopt($ch, CURLOPT_HEADER, TRUE);
	@curl_setopt($ch, CURLOPT_NOBODY, TRUE);
	@curl_setopt($ch, CURLOPT_FOLLOWLOCATION, FALSE);
	@curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
	$status = array();
	preg_match('/HTTP\/.* ([0-9]+) .*/', @curl_exec($ch) , $status);
	return ($status[1] == 200);
}

If you you don’t have CURL lib istalled you can use the php get_headers function, it returns an array with the headers:

$url = 'http://www.example.com';
print_r(get_headers($url));
print_r(get_headers($url, 1));

If you apply the preg_match function to the first element of the array you will reach the same result:

function url_exists($url) {
	$h = get_headers($url);
	$status = array();
	preg_match('/HTTP\/.* ([0-9]+) .*/', $h[0] , $status);
	return ($status[1] == 200);
}