一个用PHP获取远程网址header头信息的方法,这在采集时很有用,他可以让你判断出来,远程文件或网页是否正常,是否是404页
有二种方法,
1.用php的函数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.
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
$url = '';
print_r(get_headers($url));
print_r(get_headers($url, 1));
?>
上例的输出类似于：
Array
(
[0] => HTTP/1.1 200 OK
[1] => Date: Sat, 29 May 12:28:13 GMT
[2] => Server: Apache/1.3.27 (Unix) (Red-Hat/Linux)
[3] => Last-Modified: Wed, 08 Jan 23:11:55 GMT
[4] => ETag: "3f80f-1b6-3e1cb03b"
[5] => Accept-Ranges: bytes
[6] => Content-Length: 438
[7] => Connection: close
[8] => Content-Type: text/HTML
)
Array
(
[0] => HTTP/1.1 200 OK
[Date] => Sat, 29 May 12:28:14 GMT
[Server] => Apache/1.3.27 (Unix) (Red-Hat/Linux)
[Last-Modified] => Wed, 08 Jan 23:11:55 GMT
[ETag] => "3f80f-1b6-3e1cb03b"
[Accept-Ranges] => bytes
[Content-Length] => 438
[Connection] => close
[Content-Type] => text/html
)
get_headers 是用来取得远程服务器的响应头信息的.用返回的第一个数组再加上正则就可以判断远程地址是否为200正常网页
2,用curl CURLOPT_NOBODY参数只抓取header头信息
curl函数真是个好东西,curl参数里有一项可以配置只抓取远程网页的header头信息
如下代码,加红的地方是关健,他指定了curl抓的内容中包含header头,并且不要body内容.
function get_header($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;
}
