PHP: file_exists for remote URL

remote-file-exists.php

<?php
// More details here:
// https://vyspiansky.github.io/2017/11/09/remote-file-exists-using-get-headers/

$file_headers = @get_headers($url);

if ($file_headers[0] == 'HTTP/1.0 404 Not Found'){ // or "HTTP/1.1 404 Not Found" etc.
	$file_exists = false;
} else {
	$file_exists = true;
}

To check if allow_url_fopen is enabled or not you can use ini_get():

if (ini_get('allow_url_fopen')) {
    echo "allow_url_fopen is enabled";
}

Or just print the get_headers:

$url = 'some url here...';
$file_headers = @get_headers($url);
print_r($file_headers);

and you should see something like:

Array
(
    [0] => HTTP/1.1 200 OK
    [1] => Content-Type: image/png
    [2] => Content-Length: 127999
    [3] => Connection: close
    [4] => Date: Thu, 09 Nov 2017 12:16:51 GMT
    [5] => Last-Modified: Wed, 08 Nov 2017 09:12:17 GMT
    ...
)

Be careful, the message may have the different version of the protocol: "HTTP/1.0 404 Not Found" or "HTTP/1.1 404 Not Found" etc.

I use the following so that I do not have to worry about HTTP/1.0 or 1.1, etc.

if(strpos($file_headers[0], '404') !== false)