If you need to know a lot of intimate information about your web server and have php installed, finding it is trivial process using a php function called phpinfo().
Simply create a plain text file called myphpinfo.php in a browser accessible space on your web server, paste the following code into the file and save it:
<?php echo phpinfo();?>
Now, access the file through your browser. It will print out a trove of information about your web server and php, including the operating system, specific web server, encryption type, loaded modules and plugins, and more.
One word of advice: make sure you delete the file after you’re done. This file is basically a road map of how your server is set up and can be used to make attacks against your server easier. Seeing how easy it is to recreate the file, it’s advisable to get in the practice of destroying it instead of leaving it laying around.