在PHP中可以通过header函数来发送头信息，还可以设置文件的content-type，下面整理了一些常见文件类型对于的content-type值。
//date 2015-06-22 //定义编码 header( 'Content-Type:text/html;charset=utf-8 '); //Atom header('Content-type: application/atom+xml'); //CSS header('Content-type: text/css'); //Javascript header('Content-type: text/javascript'); //JPEG Image header('Content-type: image/jpeg'); //JSON header('Content-type: application/json'); //PDF header('Content-type: application/pdf'); //RSS header('Content-Type: application/rss+xml; charset=ISO-8859-1'); //Text (Plain) header('Content-type: text/plain'); //XML header('Content-type: text/xml'); // ok header('HTTP/1.1 200 OK'); //设置一个404头: header('HTTP/1.1 404 Not Found'); //设置地址被永久的重定向 header('HTTP/1.1 301 Moved Permanently'); //转到一个新地址 header('Location: '); //文件延迟转向: header('Refresh: 10; url=http://www.example.org/'); print 'You will be redirected in 10 seconds'; //当然，也可以使用html语法实现 // <meta http-equiv="refresh" content="10; /> // override X-Powered-By: PHP: header('X-Powered-By: PHP/4.4.0'); header('X-Powered-By: Brain/0.6b'); //文档语言 header('Content-language: en'); //告诉浏览器最后一次修改时间 $time = time() - 60; // or filemtime($fn), etc header('Last-Modified: '.gmdate('D, d M Y H:i:s', $time).' GMT'); //告诉浏览器文档内容没有发生改变 header('HTTP/1.1 304 Not Modified'); //设置内容长度 header('Content-Length: 1234'); //设置为一个下载类型 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'); // 对当前文档禁用缓存 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 past header('Pragma: no-cache'); //设置内容类型: header('Content-Type: text/html; charset=iso-8859-1'); header('Content-Type: text/html; charset=utf-8'); header('Content-Type: text/plain'); //纯文本格式 header('Content-Type: image/jpeg'); //JPG*** header('Content-Type: application/zip'); // ZIP文件 header('Content-Type: application/pdf'); // PDF文件 header('Content-Type: audio/mpeg'); // 音频文件 header('Content-Type: application/x-shockw**e-flash'); //Flash动画 //显示登陆对话框 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';