Content-Disposition: - Sending Files for Downloading

This section provides a tutorial example on how to insert the 'Content-Disposition:' header line in a HTTP response to tell the browser to prompt the user the download and save the response entity body as a file.

In the previous section, the requested file is delivered to the browser for opening immediately. HTTP does also support another header line called "Content-Disposition" which tells the browser to not open the file immediately, but prepare for downloading the entity body. The following script will show you how to do this:

<?php #GetFile.php
#- Copyright (c) 2015, HerongYang.com, All Rights Reserved.
#
   $ok = array_key_exists('QUERY_STRING', $_SERVER);
   if ($ok) {
      $p = $_SERVER['QUERY_STRING'];
      $ok = strlen($p)>0 && file_exists($p);
   }
   if ($ok) {
      if (strpos($p,".html")!=false) {
         header("Content-Type: text/html");
      } else if (strpos($p,".gif")!=false) {
         header("Content-Type: image/gif");
      } else if (strpos($p,".pdf")!=false) {
         header("Content-Type: application/pdf");
      } else if (strpos($p,".doc")!=false) {
         header("Content-Type: application/msword");
      } else {
         $ok = false;
      }
   }
   if ($ok) {
      header("Content-Length: ".filesize($p));
      header("Content-disposition: attachment; filename=".$p);
      readfile($p);
   } else {
      print("<html><body>Bad request.</body></html>");
   }
?>

In this page, another header line, "Content-Disposition", is added to the response, in which I am telling the client program that the entity data is an attachment, with file name specified.

Now try to use IE to request http://localhost/Download.php?hello.pdf, you will see IE prompting you to save the attachment instead of calling Adobe Reader to display the data.

Try to use IE to request http://localhost/Download.php?other_existing_file, you will see IE display the "Bad request" message. The script is working correctly.

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

 Creating and Managing Sessions in PHP Scripts

 Sending and Receiving Cookies in PHP Scripts

Controlling HTTP Response Header Lines in PHP Scripts

 What Is an HTTP Response?

 HTTP Response Header Lines

 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

 Introduction of Class and Object

 Integrating PHP with Apache Web Server

 Outdated Tutorials

 References

 PDF Printing Version