How to check if an external service is up and running in php

PHP
1

$url = “http://www.xyz.com/restservices/assignment/section/1/userid/2864182”;

$assignlist = @file_get_contents($url); ---- this shows a 504 Gateway Timeout error

If I directly access the url in browser then it shows “NetworkError: 503 Service Unavailable…d server is at capacity” — before calling file_get_contents function is it possible to check whether the external service is available at all or not.

2 

$host = '193.33.186.70'; 
$port = 80; 
$waitTimeoutInSeconds = 1; 
if($fp = fsockopen($host,$port,$errCode,$errStr,$waitTimeoutInSeconds)){   
   // It worked 
} else {
   // It didn't work 
} 
fclose($fp);

source: http://stackoverflow.com/questions/9841635/how-to-ping-a-server-port-with-php

Edit : file_get_contents will not work with URIs without allow_url_fopen set to ON.
You should get the content with cURL and this way you can also check if the resource is available (cURL works almost like fsockopen)

3

You might consider using the get_headers() function.
http://php.net/manual/en/function.get-headers.php

In the comments of that page, you will notice an example to get the response code.

<?php
function get_http_response_code($theURL) {
    $headers = get_headers($theURL);
    return substr($headers[0], 9, 3);
}
?>

You could then use that like…

$url = "http://www.xyz.com/restservices/assignment/section/1/userid/2864182";
$assignlist = '';
if(get_http_response_code($url) == '200') {
    $assignlist = @file_get_contents($url); 
}

The same could also be done via cURL like vectorialpx mentions.