How can I check if a server is up and running?

[electricocean]

Is there any way to check if a server is running and then refresh to it?
maybe something like this:

<?php
$url = "http://www.mysite.com";
if(server_status($url) == true){
header('location : $url');
}
else{
echo "Server down -- TRY AGAIN LATER";
}
?>

I was looking at php.net and i found Memcache::getStats(), but i don't know what that does...

Is there a way to do this?

thanks,
electricocean

[Giljorak]

I used the following to get images from my local server if my remote source(isp web space) was unavailable:

<?php
$data = include('http://myname.my.isp.net/bummer.txt');
if ($data){
 $url="http://myname.my.isp.net/";
}else{
 $url="http://local.web.storage.area.net/";
}
?>

The file bummer.txt is just an empty file on my isp's web storage area.

I did this because at the time I had limited bandwidth available for my own server and figured that my isp could serve the images faster than my wimpy DSL connection.

This has worked extremely well for me.

[electricocean]

so i could do

<?php
$url = "http://mysite.com/index.php";
$filename = include($url);
if($filename){
header('Location: $url');
}
else{
echo "Site Down--- try again later";
}
?>
thanks,
electricocean

[electricocean]

i also tried this:

<?php
$url = "http://www.mysite.com/index.php";
if(is_readable($url) && file_exists($url)){
echo "<script language=\"javascript\">
top.location.replace = \"{$url}\";
</script>";
}
else{
echo "Server down -- TRY AGAIN LATER";
}
?>

this always return fals eand outputs "Server down -- TRY AGAIN LATER".

What's wrong?