php 擷取遠程網址header頭資訊

1. 用php擷取遠程網址header頭資訊的方法,這在採集時很有用,他可以讓你判斷出來,遠程檔案或網頁是否正常,是否是404頁.

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

print_r(get_headers($url));

上例的輸出類似於：

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
)

---------------------------------------------------

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

print_r(get_headers($url, 1));

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
是用來取得遠程伺服器的回應標頭資訊的.用返回的第一個數組再加上正則就可以判斷遠程地址是否為200正常網頁

--------------------------------------------------------------

2. 用curl
CURLOPT_NOBODY參數只抓取header頭資訊

curl函數真是個好東西,curl參數裡有一項可以配置只抓取遠程網頁的header頭資訊

如下代碼,他指定了curl抓的內容中包含header頭,並且不要body內容.

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;
}