get_headers — 取得服务器响应一个 HTTP 请求所发送的所有标头
array get_headers ( string $url [, int $format ] )
如果地址有效则返回一个数组，否则返回false,当第二个参数为1时，会解析相应的信息并设定数组的键名，返回关联数组
eg:
<?php$url = 'http://www.investfree-brk.com';print_r(get_headers($url));print_r(get_headers($url, 1));?>
以上结果输出如下：
Array ( [0] => HTTP/1.1 200 OK [1] => Date: Sat, 29 May 2004 12:28:13 GMT [2] => Server: Apache/1.3.27 (Unix) (Red-Hat/Linux) [3] => Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT [4] => ETag: "3f80f-1b6-3e1cb03b" [5] => Accept-Ranges: bytes [6] => Content-Length: 438 [7] => Connection: close [8] => Content-Type: text/html ) Array ( [0] => HTTP/1.1 200 OK [Date] => Sat, 29 May 2004 12:28:14 GMT [Server] => Apache/1.3.27 (Unix) (Red-Hat/Linux) [Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT [ETag] => "3f80f-1b6-3e1cb03b" [Accept-Ranges] => bytes [Content-Length] => 438 [Connection] => close [Content-Type] => text/html )转载于:https://www.cnblogs.com/watermelon-cmj/p/9256268.html
