How to set content type in php

//author <a href="http://www.lai18.com" target="_blank">http://www.lai18.com</a>   
//date 2015-06-22  
//定义编码  
header( &#39;Content-Type:text/html;charset=utf-8 &#39;);  
  
//Atom  
header(&#39;Content-type: application/atom+xml&#39;);  
  
//CSS  
header(&#39;Content-type: text/css&#39;);  
  
//Javascript  
header(&#39;Content-type: text/javascript&#39;);  
  
//JPEG Image  
header(&#39;Content-type: image/jpeg&#39;);  
  
//JSON  
header(&#39;Content-type: application/json&#39;);  
  
//PDF  
header(&#39;Content-type: application/pdf&#39;);  
  
//RSS  
header(&#39;Content-Type: application/rss+xml; charset=ISO-8859-1&#39;);  
  
//Text (Plain)  
header(&#39;Content-type: text/plain&#39;);  
  
//XML  
header(&#39;Content-type: text/xml&#39;);  
  
// ok  
header(&#39;HTTP/1.1 200 OK&#39;);  
  
//设置一个404头:  
header(&#39;HTTP/1.1 404 Not Found&#39;);  
  
//设置地址被永久的重定向  
header(&#39;HTTP/1.1 301 Moved Permanently&#39;);  
  
//转到一个新地址  
header(&#39;Location: <a style="color:rgb(51,119,170); text-decoration:none" href="http://www.example.org/" target="_blank">http://www.example.org/&#39;);</a>   
//文件延迟转向:  
header(&#39;Refresh: 10; url=http://www.example.org/&#39;);  
print &#39;You will be redirected in 10 seconds&#39;;  
  
//当然，也可以使用html语法实现  
// <meta http-equiv="refresh" content="10;http://www.example.org/ />  
  
// override X-Powered-By: PHP:  
header(&#39;X-Powered-By: PHP/4.4.0&#39;);  
header(&#39;X-Powered-By: Brain/0.6b&#39;);  
  
//文档语言  
header(&#39;Content-language: en&#39;);  
  
//告诉浏览器最后一次修改时间  
$time = time() - 60; // or filemtime($fn), etc  
header(&#39;Last-Modified: &#39;.gmdate(&#39;D, d M Y H:i:s&#39;, $time).&#39; GMT&#39;);  
  
//告诉浏览器文档内容没有发生改变  
header(&#39;HTTP/1.1 304 Not Modified&#39;);  
  
//设置内容长度  
header(&#39;Content-Length: 1234&#39;);  
  
//设置为一个下载类型  
header(&#39;Content-Type: application/octet-stream&#39;);  
header(&#39;Content-Disposition: attachment; filename="example.zip"&#39;);  
header(&#39;Content-Transfer-Encoding: binary&#39;);  
// load the file to send:  
readfile(&#39;example.zip&#39;);  
  
// 对当前文档禁用缓存  
header(&#39;Cache-Control: no-cache, no-store, max-age=0, must-revalidate&#39;);  
header(&#39;Expires: Mon, 26 Jul 1997 05:00:00 GMT&#39;); // Date in the past  
header(&#39;Pragma: no-cache&#39;);  
  
//设置内容类型:  
header(&#39;Content-Type: text/html; charset=iso-8859-1&#39;);  
header(&#39;Content-Type: text/html; charset=utf-8&#39;);  
header(&#39;Content-Type: text/plain&#39;); //纯文本格式  
header(&#39;Content-Type: image/jpeg&#39;); //JPG***  
header(&#39;Content-Type: application/zip&#39;); // ZIP文件  
header(&#39;Content-Type: application/pdf&#39;); // PDF文件  
header(&#39;Content-Type: audio/mpeg&#39;); // 音频文件  
header(&#39;Content-Type: application/x-shockw**e-flash&#39;); //Flash动画  
  
//显示登陆对话框  
header(&#39;HTTP/1.1 401 Unauthorized&#39;);  
header(&#39;WWW-Authenticate: Basic realm="Top Secret"&#39;);  
print &#39;Text that will be displayed if the user hits cancel or &#39;;  
print &#39;enters wrong login data&#39;;