get_headers() 是PHP系统级函数，他返回一个包含有服务器响应一个 HTTP 请求所发送的标头的数组。如果失败则返回 FALSE 并发出一条 E_WARNING 级别的错误信息(可用来判断远程文件是否存在)。 [b]函数定义[/b] array get_headers ( string $url [, int $format = 0 ] ) [b]参数[/b] [b]url 目标 URL[/b] format 如果将可选的 format 参数设为 1，则 get_headers() 会解析相应的信息并设定数组的键名。 [b]示例[/b] <?php $url='http://www.phpernote.com'; print_r(get_headers($url)); print_r(get_headers($url,1)); ?> [b]以上例程的输出类似于：[/b] [b]Array [/b](     [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 ) [b]Array [/b](     [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 )