Check if server is online?

[Kevin Evans]

T-T
I can't figure this out. I'm trying to check if a server is online, and I need to do it efficiently. I have no idea where to start, i've tried AJAX, but it doesn't really check if the server is online (it only checks if the URL is malformed)

I know somebody knows how to do this!!

So... anyone wanna help me fill this out? :3

function serverOnline(var server){

return false;
}

<3
thanks

[Swooter]

You could use a PHP script like this:

pingdomain.php

PHP Code:

<?php
 
function pingDomain($domain){
    $starttime = microtime(true);
    $file      = fsockopen ($domain, 80, $errno, $errstr, 10);
    $stoptime  = microtime(true);
    $status    = 0;
 
    if (!$file) $status = -1;  // Site is down
    else {
        fclose($file);
        $status = ($stoptime - $starttime) * 1000;
        $status = floor($status);
    }
    return $status;
}
echo pingDomain($_GET["domain"]);
 
?>

And then load it with xmlhttp:
pingdomain.php?domain=www.kirupa.com

and then check whether the responseText is 0 or -1

[actionAction]

Use jQuery ajax call with the timeout variable set:

function checkServer(server){
    //assume it is not online
    var active = false;
     $.ajax({
        url: 'http://www.'+server,
        timeout: 3000, //set the timeout to 3 seconds
        success: function(){
            active = true;
        },
        error: function(req, err){
           if(err == 'timeout'){
              console.log('Server: %s timed out', server);
           }
        }
     });
     return active;
}

[actionAction]

Nevermind, I am braindead. You can't do remote XHR requests, duh! Anyway, if there is a static set of servers and you are wanting to keep this in Javascript, you can look for an image (that you know will exist) and see if it is there or not:

    var img = new Image();
    //This is a yahoo image
    img.src ='http://l.yimg.com/a/i/mntl/ww/events/p.gif';
    img.onerror = function(){
        console.log('Problem loading remote image');
    }