§Your friend phpinfo().

Phpinfo is a little tool to inspect your PHP install.. It tells you what version is running, whether or not the ghastly safe_mode or the horrendous open_basedir-restriction is in effect.

What you should do is upload a small file called phpinfo.php to your webserver, and access it through your browser. If your server does not run php, it will look like this:

 <?php 
 echo "version is: <b>".phpversion()."</b><br>\n"; 
 echo "Lots of info: <br>\n" 
 phpinfo(); 
 ?> 

If, however, you get a screen like this, you have a working PHP install:

It will tell you the version of your PHP install, the typ eof server it is on, and whether or not it is running in safe_mode.