Check if submitted string is a url? - php

Question

so i have this website where people can submit url's for certain items, but I dont know how i can validate that a url was submitted not just some crap!.
Atm i have this piece of code:
if(filter_var('http://www.example.com/test.html', FILTER_VALIDATE_URL)) {
echo 'this is URL';
} else {
echo 'this is no url!';
}
But this piece of code is easy to bypass since it only checks for "http" in the string,
And users will submit "host" separately so i need to check if $host is a valid host.
Thx in advance! you guys rock!

Answer 1

Here is an example that solves your problem :
<?php
$url = "http://www.example.com/test.html";
if (preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&##\/%?=~_|!:,.;]*[-a-z0-9+&##\/%=~_|]/i", $url)) {
echo "URL is valid";
}
else {
echo "URL is invalid";
}
?>

Answer 2

How about sending it an HTTP request?
function isValid($url) {
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_NOBODY, true); //make it a HEAD request
curl_exec($curl);
$statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE);
curl_close($curl);
return $statusCode == 200;
}
var_dump(isValid('http://www.google.co.uk')); // bool(true)
var_dump(isValid('some invalid URL')); // bool(false)