#### get_headers()
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get_headers — 取得服务器响应一个 HTTP 请求所发送的所有标头
##### 说明
array get_headers ( string $url [, int $format = 0 ] )
get_headers() 返回一个数组,包含有服务器响应一个 HTTP 请求所发送的标头。
##### 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。
##### 返回值
返回包含有服务器响应一个 HTTP 请求所发送标头的索引或关联数组,如果失败则返回 FALSE。
### 范例
Example #1 get_headers() 例子
~~~
<?php
$url = 'http://www.example.com';
print_r(get_headers($url));
print_r(get_headers($url, 1));
?>
~~~
以上例程的输出类似于:
~~~
Array
(
[0] => HTTP/1.1 200 OK
[1] => Date: Sat, 29 May 2004 12:28:13 GMT
[2] => Server: Apache/1.3.27 (Unix) (Red-Hat/Linux)
[3] => Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT
[4] => ETag: "3f80f-1b6-3e1cb03b"
[5] => Accept-Ranges: bytes
[6] => Content-Length: 438
[7] => Connection: close
[8] => Content-Type: text/html
)
Array
(
[0] => HTTP/1.1 200 OK
[Date] => Sat, 29 May 2004 12:28:14 GMT
[Server] => Apache/1.3.27 (Unix) (Red-Hat/Linux)
[Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT
[ETag] => "3f80f-1b6-3e1cb03b"
[Accept-Ranges] => bytes
[Content-Length] => 438
[Connection] => close
[Content-Type] => text/html
)
~~~
获取返回码:
~~~
<?php
function get_http_response_code($theURL) {
$headers = get_headers($theURL);
return substr($headers[0], 9, 3);
}
if(intval(get_http_response_code('filename.jpg')) < 400){
// File exists, huzzah!
}
?>
~~~
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http://php.net/manual/zh/function.get-headers.php