PHP header的一些用法

<?php
//PHP header()函数用法
/*** Function: PHP header() examples (PHP)
*/

// 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';


/*------------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;
    }

/**********下載2************/
if (!@fopen($file,"r")) { die("404 File not found!"); }
header('Expires: 0');
header('Pragma: public');
header('Connection: close');
header('Cache-Control: no-cache,must-revalidate');
header('Content-Transfer-Encoding: binary');
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
//header('Content-Length: ' . filesize($file));
@readfile($file);