Operating System Information in $_SERVER

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) 2015, HerongYang.com, All Rights Reserved.
# 
   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: 2015.

Table of Contents

 About This Book

 Introduction and Installation of PHP 7.0

 PHP Script File Syntax

 PHP Data Types and Data Literals

 Variables, References, and Constants

 Expressions, Operations and Type Conversions

 Conditional Statements - "if" and "switch"

 Loop Statements - "while", "for", and "do ... while"

 Function Declaration, Arguments, and Return Values

 Arrays - Ordered Maps

 Configuring and Sending out Emails

Retrieving Information from HTTP Requests

 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

 Creating and Managing Sessions in PHP Scripts

 Sending and Receiving Cookies in PHP Scripts

 Controlling HTTP Response Header Lines in PHP Scripts

 MySQL Server Connection and Access Functions

 Functions to Manage Directories, Files and Images

 SOAP Extension Function and Calling Web Services

 SOAP Server Functions and Examples

 Localization Overview of Web Applications

 Using Non-ASCII Characters in HTML Documents

 Using Non-ASCII Characters as PHP Script String Literals

 Receiving Non-ASCII Characters from Input Forms

 "mbstring" Extension and Non-ASCII Encoding Management

 Managing Non-ASCII Character Strings with MySQL Servers

 Introduction of Class and Object

 Integrating PHP with Apache Web Server

 Outdated Tutorials

 References

 PDF Printing Version