怎樣使用php 獲取遠程網(wǎng)址頭部信息

在PHP網(wǎng)站建設一個用php獲取遠程網(wǎng)址header頭信息的方法,這在采集時很有用,他可以讓你判斷出來,遠程文件或網(wǎng)頁是否正常,是否是404頁

有二種方法,

1.用php的函數(shù)get_headers
get_headers -- Fetches all the headers sent by the server in response to a HTTP request
Description
array get_headers ( string url [, int format] )
get_headers() returns an array with the headers sent by the server in response to a HTTP request. Returns FALSE on failure and an error of level E_WARNING will be issued.

www.diyphp.net

If the optional format parameter is set to 1, get_headers() parses the response and sets the array's keys.

例子 1. get_headers() example

<?php
$url = 'http://www.example.com';
print_r(get_headers($url));

print_r(get_headers($url, 1));
?>
上例的輸出類似于：

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
)

get_headers 是用來取得遠程服務器的響應頭信息的.用返回的第一個數(shù)組再加上正則就可以判斷遠程地址是否為200正常網(wǎng)頁

2,用curl CURLOPT_NOBODY參數(shù)只抓取header頭信息

curl函數(shù)真是個好東西,curl參數(shù)里有一項可以配置只抓取遠程網(wǎng)頁的header頭信息

如下代碼,加紅的地方是關健,他指定了curl抓的內(nèi)容中包含header頭,并且不要body內(nèi)容.

function get_header($url){
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_NOBODY,true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION,true);
curl_setopt($ch, CURLOPT_AUTOREFERER,true);
curl_setopt($ch, CURLOPT_TIMEOUT,30);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Accept: */*',
'User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)',
'Connection: Keep-Alive'));
$header = curl_exec($ch);
return $header;
}