$_SERVER数组属于超全局数组变量。$_SERVER数组包含了一系列由web服务器创建的数据，编程过程中，可以使用$_SERVER数组很轻易的获得和服务端相关的数据。$_SERVER数组包换了例如：头信息、服务器主机名、PHP的文件信息等等。

举个例子：我使用print_r()打印出我本地的服务端相关数据。

<?php




echo '<pre>';




print_r($_SERVER);




?>

它列出了我本地服务器上$_SERVER数组的内容。如下：

Array




(




    [COMSPEC] => C:\WINDOWS\system32\cmd.exe




    [DOCUMENT_ROOT] => e:/bae




    [HTTP_ACCEPT] => text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8




    [HTTP_ACCEPT_CHARSET] => GBK,utf-8;q=0.7,*;q=0.3




    [HTTP_ACCEPT_ENCODING] => gzip,deflate,sdch




    [HTTP_ACCEPT_LANGUAGE] => zh-CN,zh;q=0.8




    [HTTP_CONNECTION] => keep-alive




    [HTTP_COOKIE] => bdshare_firstime=1356335743658; CNZZDATA2262423=cnzz_eid=29272136-1359802178-&ntime=1359802178&cnzz_a=0&retime=1359802497789&sin=<ime=1359802497789&rtime=0; USR=cmtbinvi%0974%091361783123%09http%3A%2F%2Flocalhost%2Fshunde56%2F




    [HTTP_HOST] => localhost




    [HTTP_REFERER] => http://localhost/




    [HTTP_USER_AGENT] => Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11




    [PATH] => C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;F:\cpu37king\Subversion\bin;D:\Program Files\Subversion\bin;D:\Program Files\TortoiseSVN\bin;




    [REDIRECT_STATUS] => 200




    [REDIRECT_URL] => /edu/




    [REMOTE_ADDR] => 127.0.0.1




    [REMOTE_PORT] => 1719




    [SCRIPT_FILENAME] => e:/bae/edu/index.php




    [SERVER_ADDR] => 127.0.0.1




    [SERVER_ADMIN] => [no address given]




    [SERVER_NAME] => 127.0.0.1




    [SERVER_PORT] => 80




    [SERVER_SIGNATURE] => 




Apache/1.3.33 Server at 127.0.0.1 Port 80




    [SERVER_SOFTWARE] => Apache/1.3.33 (Win32) PHP/5.1.2




    [SystemRoot] => C:\WINDOWS




    [WINDIR] => C:\WINDOWS




    [GATEWAY_INTERFACE] => CGI/1.1




    [SERVER_PROTOCOL] => HTTP/1.1




    [REQUEST_METHOD] => GET




    [QUERY_STRING] => 




    [REQUEST_URI] => /edu/




    [SCRIPT_NAME] => /edu/index.php




    [PATH_TRANSLATED] => e:/bae/edu/index.php




    [PHP_SELF] => /edu/index.php




    [REQUEST_TIME] => 1361867733




)