php中get_headers函数的作用及用法的详细介绍

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)。

函数定义

array get_headers ( string $url [, int $format = 0 ] )

参数

url 目标 URL

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。

示例

<?php

$url='http://www.phpernote.com';

print_r(get_headers($url));

print_r(get_headers($url,1));

?>

以上例程的输出类似于：

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

)