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 2003 (c) 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:
   ALLUSERSPROFILE = C:\ProgramData
   CommonProgramFiles = C:\Program Files\Common Files
   CommonProgramFiles(x86) = C:\Program Files (x86)\Common Files
   CommonProgramW6432 = C:\Program Files\Common Files
   ComSpec = C:\windows\system32\cmd.exe
   configsetroot = C:\windows\ConfigSetRoot
   FP_NO_HOST_CHECK = NO
   ProgramData = C:\ProgramData
   ProgramFiles = C:\Program Files
   ProgramFiles(x86) = C:\Program Files (x86)
   ProgramW6432 = C:\Program Files
   PROMPT = $P$G
   ......
</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.

Table of Contents

 About This Book

 Introduction and Installation of PHP

 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

 Interface with Operating System

 Introduction of Class and Object

 Integrating PHP with Apache Web Server

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

 Managing File Upload

 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

 Parsing and Managing HTML Documents

 Configuring and Sending Out Emails

 Image and Picture Processing

 Managing ZIP Archive Files

 Managing PHP Engine and Modules on macOS

 Managing PHP Engine and Modules on CentOS

 Archived Tutorials

 References

 Full Version in PDF/EPUB