php只抓取网页头的方法:1、使用get_headers()函数;2、使用http_response_header方法;3、使用stream_get_meta_data()函数;4、使用php CURL来获取网页头即可。
本文操作环境:windows7系统、PHP7.1版、DELL G3电脑
php如何只抓取网页头?
php获取网页header信息的4种方法
php获取网页header信息的方法多种多样,就php语言来说,我知道的方法有4种, 下面逐一献上。
方法一:使用get_headers()函数
推荐指数: ★★★★★
get_header方法最简单只要两行代码即可搞定。如下:
$thisurl = "http://www.lao8.org/"; print_r(get_headers($thisurl, 1));
得到的结果为:
Array ( [0] => HTTP/1.1 200 OK [Cache-Control] => max-age=86400 [Content-Length] => 76102 [Content-Type] => text/html [Content-Location] => http://www.lao8.org/index.html [Last-Modified] => Fri, 19 Jul 2013 03:52:30 GMT [Accept-Ranges] => bytes [ETag] => "50bc48643384ce1:5cb3" [Server] => Microsoft-IIS/6.0 [X-Powered-By] => ASP.NET [Date] => Fri, 19 Jul 2013 09:06:39 GMT [Connection] => close )
方法二:使用http_response_header
推荐指数: ★★★
http_response_headerf方法也很简单,仅三行:
$thisurl = "http://www.lao8.org"; $html = file_get_contents($thisurl ); print_r($http_response_header);
得到的结果为:
Array ( [0] => HTTP/1.1 200 OK [1] => Cache-Control: max-age=86400 [2] => Content-Length: 76102 [3] => Content-Type: text/html [4] => Content-Location: http://www.lao8.org/index.html [5] => Last-Modified: Fri, 19 Jul 2013 03:52:30 GMT [6] => Accept-Ranges: bytes [7] => ETag: "50bc48643384ce1:5cb3" [8] => Server: Microsoft-IIS/6.0 [9] => X-Powered-By: ASP.NET [10] => Date: Fri, 19 Jul 2013 09:06:41 GMT [11] => Connection: close )
方法三:使用stream_get_meta_data()函数
推荐指数: ★★★
使用stream_get_meta_data()代码也只需三行:
$thisurl = "http://www.lao8.org/"; $fp = fopen($thisurl, 'r'); print_r(stream_get_meta_data($fp));
得到的结果为:
Array ( [wrapper_data] => Array ( [0] => HTTP/1.1 200 OK [1] => Cache-Control: max-age=86400 [2] => Content-Length: 76102 [3] => Content-Type: text/html [4] => Content-Location: http://www.lao8.org/index.html [5] => Last-Modified: Fri, 19 Jul 2013 03:52:30 GMT [6] => Accept-Ranges: bytes [7] => ETag: "50bc48643384ce1:5cb3" [8] => Server: Microsoft-IIS/6.0 [9] => X-Powered-By: ASP.NET [10] => Date: Fri, 19 Jul 2013 09:06:41 GMT [11] => Connection: close ) [wrapper_type] => http [stream_type] => tcp_socket [mode] => r+ [unread_bytes] => 1086 [seekable] => [uri] => http://www.lao8.org/ [timed_out] => [blocked] => 1 [eof] => )
第四种方法: 使用php的高级函数 CURL()来获取
推荐指数: ★★★★
上面的三种方法能获取一般的网页header信息,如果想要获取更详细的header信息比如网页是否启用了GZip压缩。这时候可以用php的高级函数curl()来获取。
使用curl获得header可以检测GZip压缩
先贴出代码:
<?php $szUrl = 'http://www.lao8.org/'; $curl = curl_init(); curl_setopt($curl, CURLOPT_URL, $szUrl); curl_setopt($curl, CURLOPT_HEADER, 1); //输出header信息 curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1); //不显示网页内容 curl_setopt($curl, CURLOPT_ENCODING, ''); //允许执行gzip $data=curl_exec($curl); if(!curl_errno($curl)) { $info = curl_getinfo($curl); $httpHeaderSize = $info['header_size']; //header字符串体积 $pHeader = substr($data, 0, $httpHeaderSize); //获得header字符串 $split = array("rn", "n", "r"); //需要格式化header字符串 $pHeader = str_replace($split, '<br>', $pHeader); //使用<br>换行符格式化输出到网页上 echo $pHeader; } ?>
输出结果如下:
HTTP/1.1 200 OK Cache-Control: max-age=86400 Content-Length: 15189 Content-Type: text/html Content-Encoding: gzip Content-Location: http://www.lao8.org/index.html Last-Modified: Fri, 19 Jul 2013 03:52:28 GMT Accept-Ranges: bytes ETag: "0268633384ce1:5cb3" Vary: Accept-Encoding Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET Date: Fri, 19 Jul 2013 09:27:21 GMT
可以看到使用curl获取到的header信息多了这行:Content-Encoding: gzip,网页启用了GZip压缩。
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