Operating System Information in $_SERVER

<< Retrieving Information from HTTP Requests

<< PHP Tutorials - Herong's Tutorial Examples

This section provides a tutorial example on how to dump operating system information stored in the $_SERVER array.

To help us understand how predefined variables, $_GET, $_POST, $_COOKIE, $_REQUEST, and $_SERVER, work, I wrote the following tutorial example script:

<?php # HttpRequestDetails.php
# Copyright (c) 2002 by Dr. Herong Yang, http://www.herongyang.com/
# 
   print "<pre>\n";
   print "\nContents of \$_GET:\n";
   foreach ($_GET as $k => $v) {
      print "   $k = $v\n";
   }
# 
   print "\nContents of \$_POST:\n";
   foreach ($_POST as $k => $v) {
      print "   $k = $v\n";
   }
# 
   print "\nContents of \$_COOKIE:\n";
   foreach ($_COOKIE as $k => $v) {
      print "   $k = $v\n";
   }
# 
   print "\nContents of \$_REQUEST:\n";
   foreach ($_REQUEST as $k => $v) {
      print "   $k = $v\n";
   }
# 
   print "\nContents of \$_SERVER:\n";
   foreach ($_SERVER as $k => $v) {
      print "   $k = $v\n";
   }
   print "</pre>\n";
?>

If you run this example script standalone without using any Web server, you should get:

<pre>

Contents of $_GET:

Contents of $_POST:

Contents of $_COOKIE:

Contents of $_REQUEST:

Contents of $_SERVER:
   CLIENTNAME = Console
   ComSpec = C:\WINDOWS\system32\cmd.exe
   HOMEDRIVE = C:
   PHPRC = c:\php
   PROCESSOR_ARCHITECTURE = x86
   SESSIONNAME = Console
   SystemDrive = C:
   SystemRoot = C:\WINDOWS
   PHP_SELF = HttpRequestDetails.php
   SCRIPT_NAME = HttpRequestDetails.php
   SCRIPT_FILENAME = HttpRequestDetails.php
   PATH_TRANSLATED = HttpRequestDetails.php
   DOCUMENT_ROOT =
   argv = Array
   argc = 1
   ......
</pre>

Note that $_GET, $_POST, $_COOKIE, and $_REQUEST are all empty, because we executed the script without any HTTP request. $_SERVER contains only information gathered from the operating system.

Last update: 2005.

Sections in This Chapter

Predefined Variables Related to HTTP Requests

Operating System Information in $_SERVER

Web Server Information in $_SERVER

Information in $_GET and $_REQUEST

Registering $_REQUEST Keys as Global Variables