PHP获取http请求的头信息实现步骤

PHP手册提供了现成的函数：
getallheaders
(PHP 4, PHP 5)
getallheaders — Fetch all HTTP request headers
说明
array getallheaders ( void )
Fetches all HTTP headers from the current request.
This function is an alias for apache_request_headers(). Please read theapache_request_headers() documentation for more information on how this function works.
返回值
An associative array of all the HTTP headers in the current request, orFALSE on failure.
Example #1 getallheaders() example

<?php 
foreach (getallheaders() as $name => $value) { 
echo "$name: $value\n"; 
} 
?>

不过这个函数只能在apache环境下使用，iis或者nginx并不支持，可以通过自定义函数实现

<?php 
<SPAN class=html>if (!function_exists('getallheaders')) 
{ 
    function getallheaders() 
    { 
       foreach ($_SERVER as $name => $value) 
       { 
           if (substr($name, 0, 5) == 'HTTP_') 
           { 
               $headers[str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))))] = $value; 
           } 
       } 
       return $headers; 
    } 
}</SPAN> 
?>

好了，看看都打印出了啥吧

<?php 
print_r(getallheaders());

获得结果：

Array 
( 
[Accept] => */* 
[Accept-Language] => zh-cn 
[Accept-Encoding] => gzip, deflate 
[User-Agent] => Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727) 
[Host] => localhost 
[Connection] => Keep-Alive 
)