php header 用法 php header 应用 header 函数

PHP header()函数用法
[codes=php]
/*** Function: PHP header() examples (PHP)
** Desc: Some examples on how to use the header() function of PHPYou find a detailed tutorial at expertsrt.com (English) or at ffm.junetz.de (German).These is also a good help about caching at web-caching.com.
** Example: see below. <br/><br/><b>Tip:</b> You can use these sites to check your headers: <a href="http://web-sniffer.net/">web-sniffer.net</a>, <a href="http://www.delorie.com/web/headers.html">delorie.com</a> or <a href="http://www.forret.com/projects/analyze/">www.forret.com</a>.
** Author: Jonas John
*/

// fix 404 pages:
header('HTTP/1.1 200 OK');

// set 404 header:
header('HTTP/1.1 404 Not Found');

// set Moved Permanently header (good for redrictions)
// use with location header
header('HTTP/1.1 301 Moved Permanently');

// redirect to a new location:
header('Location: http://www.example.org/');

// redrict with delay:
header('Refresh: 10; url=http://www.example.org/');
print 'You will be redirected in 10 seconds';

// you could also use the HTML syntax:// <meta http-equiv="refresh" content="10;http://www.example.org/ />

// override X-Powered-By: PHP:
header('X-Powered-By: PHP/4.4.0');
header('X-Powered-By: Brain/0.6b');

// content language (en = English)
header('Content-language: en');

// last modified (good for caching)
$time = time() – 60; // or filemtime($fn), etc
header('Last-Modified: '.gmdate('D, d M Y H:i:s', $time).' GMT');

// header for telling the browser that the content
// did not get changed
header('HTTP/1.1 304 Not Modified');

// set content length (good for caching):
header('Content-Length: 1234');

// Headers for an download:
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="example.zip"');
header('Content-Transfer-Encoding: binary');

// load the file to send:readfile('example.zip');
// Disable caching of the current document:
header('Cache-Control: no-cache, no-store, max-age=0, must-revalidate');
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
// Date in the pastheader('Pragma: no-cache');
// set content type:
header('Content-Type: text/html; charset=iso-8859-1');
header('Content-Type: text/html; charset=utf-8');
header('Content-Type: text/plain');

// plain text file
header('Content-Type: image/jpeg');

// JPG picture
header('Content-Type: application/zip');

// ZIP file
header('Content-Type: application/pdf');

// PDF file
header('Content-Type: audio/mpeg');

// Audio MPEG (MP3,…) file
header('Content-Type: application/x-shockwave-flash');

// Flash animation// show sign in box
header('HTTP/1.1 401 Unauthorized');
header('WWW-Authenticate: Basic realm="Top Secret"');
print 'Text that will be displayed if the user hits cancel or ';
print 'enters wrong login data';?>[/codes]

代码来自：http://codedump.jonasjohn.de/download/headers.txt
//下面是http://www.php.net/manual/en/function.header.php
的例子用于下载文件用
function dl_file($file){

//First, see if the file exists
if (!is_file($file)) { die(“404 File not found!“); }

//Gather relevent info about file
$len = filesize($file);
$filename = basename($file);
$file_extension = strtolower(substr(strrchr($filename,”.”),1));

//This will set the Content-Type to the appropriate setting for the file
switch( $file_extension ) {
case “pdf”: $ctype=”application/pdf”; break;
case “exe”: $ctype=”application/octet-stream”; break;
case “zip”: $ctype=”application/zip”; break;
case “doc”: $ctype=”application/msword”; break;
case “xls”: $ctype=”application/vnd.ms-excel”; break;
case “ppt”: $ctype=”application/vnd.ms-powerpoint”; break;
case “gif”: $ctype=”image/gif”; break;
case “png”: $ctype=”image/png”; break;
case “jpeg”:
case “jpg”: $ctype=”image/jpg”; break;
case “mp3″: $ctype=”audio/mpeg”; break;
case “wav”: $ctype=”audio/x-wav”; break;
case “mpeg”:
case “mpg”:
case “mpe”: $ctype=”video/mpeg”; break;
case “mov”: $ctype=”video/quicktime”; break;
case “avi”: $ctype=”video/x-msvideo”; break;

//The following are for extensions that shouldn’t be downloaded (sensitive stuff, like php files)
case “php”:
case “htm”:
case “html”:
case “txt”: die(“Cannot be used for “. $file_extension .” files!“); break;

default: $ctype=”application/force-download”;
}

//Begin writing headers
header(“Pragma: public”);
header(“Expires: 0″);
header(“Cache-Control: must-revalidate, post-check=0, pre-check=0″);
header(“Cache-Control: public”);
header(“Content-Description: File Transfer”);

//Use the switch-generated Content-Type
header(“Content-Type: $ctype”);

//Force the download
$header=”Content-Disposition: attachment; filename=”.$filename.”;”;
header($header );
header(“Content-Transfer-Encoding: binary”);
header(“Content-Length: “.$len);
@readfile($file);
exit;
}

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