PHP Tutorials - Herong's Tutorial Examples - Version 4.20, by Dr. Herong Yang
HttpRequestGet.php - Viewing Header Lines
This section provides a tutorial example script, HttpRequestGet.php, on how to dump the entire HTTP response including all header lines from a Web server.
When a client program receives an HTTP response, it will look at header lines first. Based on the information contained in header lines, the client program will decide what to do with the actual response data in the entity body.
If you use a Web browser as an HTTP client program, it will process the data in the entity body differently depending on mainly the "Content-Type" entity header line: displaying the data as it is, rendering the data as an HTML document and displaying the resulting information, or passing the data to another registered program to handle it.
Once the Web browser finishes processing the entity body, you can get some limited information from the header lines. For example, you can click the right mouse button and select the properties command on Internet Explorer, it will display some general properties about this response in a pop up window. Properties displayed are not always identical to response header lines. The "Modified" property is probably identical to the "Last-Modified" entity header line. The "Type" property is sometime related to the "Content-Type" entity header line, and sometimes related to server side resource that generated the response.
How to view all header lines received in an HTTP response? I couldn't easily find any existing tools to do this. So I wrote the following program to dump the entire response including all header lines received from a Web server:
<?php # HttpRequestGet.php #- Copyright (c) 2003-2019, HerongYang.com, All Rights Reserved. # $path = "/index.html"; $port = 80; $host = "localhost"; if (count($argv) > 1) $path = $argv[1]; if (count($argv) > 2) $port = $argv[2]; if (count($argv) > 3) $host = $argv[3]; $address = gethostbyname($host); $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP); socket_connect($socket, $address, $port); $in = "GET $path HTTP/1.0\r\n\r\n"; socket_write($socket, $in, strlen($in)); while ($out = socket_read($socket, 2048)) { echo $out; } socket_close($socket); ?>
Note that:
Last update: 2019.
Table of Contents
Introduction and Installation of PHP 7.3
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
Introduction of Class and Object
Integrating PHP with Apache Web Server
Retrieving Information from HTTP Requests
Creating and Managing Sessions in PHP Scripts
Sending and Receiving Cookies in PHP Scripts
►Controlling HTTP Response Header Lines in PHP Scripts
header() - Inserting a Raw Header Lines
►HttpRequestGet.php - Viewing Header Lines
Response Header Lines of Static Files
HttpHeaderLines.php - Examples of Inserting Header Lines
Location: - Forcing the Browser to Redirect to Another URL
Content-Type: - Generating Non-HTML Response Body
Content-Disposition: - Sending Files for Downloading
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