php file_get_contents抓取Gzip网页乱码的三种解决方法
php file_get_contents抓取Gzip网页乱码的三种解决方法
发布时间:2016-12-29 来源:查字典编辑
摘要:把抓取到的内容转下编码即可($content=iconv("GBK","UTF-8//IGNORE",$content);),我们这里讨论的...

把抓取到的内容转下编码即可($content=iconv("GBK", "UTF-8//IGNORE", $content);),我们这里讨论的是如何抓取开了Gzip的页面。怎么判断呢?获取的头部当中有Content-Encoding: gzip说明内容是GZIP压缩的。用FireBug看一下就知道页面开了gzip没有。下面是用firebug查看我的博客的头信息,Gzip是开了的。

复制代码 代码如下:

请求头信息原始头信息

Accepttext/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Accept-Encodinggzip, deflate

Accept-Languagezh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3

Connectionkeep-alive

Cookie__utma=225240837.787252530.1317310581.1335406161.1335411401.1537; __utmz=225240837.1326850415.887.3.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=%E4%BB%BB%E4%BD%95%E9%A1%B9%E7%9B%AE%E9%83%BD%E4%B8%8D%E4%BC%9A%E9%82%A3%E4%B9%88%E7%AE%80%E5%8D%95%20site%3Awww.nowamagic.net; PHPSESSID=888mj4425p8s0m7s0frre3ovc7; __utmc=225240837; __utmb=225240837.1.10.1335411401

Hostwww.nowamagic.net

User-AgentMozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20100101 Firefox/12.0

下面介绍一些解决方案:

1. 使用自带的zlib库

如果服务器已经装了zlib库,用下面的代码可以轻易解决乱码问题。

复制代码 代码如下:

$data = file_get_contents("compress.zlib://".$url);

2. 使用CURL代替file_get_contents

复制代码 代码如下:

function curl_get($url, $gzip=false){

$curl = curl_init($url);

curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 10);

if($gzip) curl_setopt($curl, CURLOPT_ENCODING, "gzip"); // 关键在这里

$content = curl_exec($curl);

curl_close($curl);

return $content;

}

3. 使用gzip解压函数

复制代码 代码如下:

function gzdecode($data) {

$len = strlen($data);

if ($len < 18 || strcmp(substr($data,0,2),"x1fx8b")) {

return null; // Not GZIP format (See RFC 1952)

}

$method = ord(substr($data,2,1)); // Compression method

$flags = ord(substr($data,3,1)); // Flags

if ($flags & 31 != $flags) {

// Reserved bits are set -- NOT ALLOWED by RFC 1952

return null;

}

// NOTE: $mtime may be negative (PHP integer limitations)

$mtime = unpack("V", substr($data,4,4));

$mtime = $mtime[1];

$xfl = substr($data,8,1);

$os = substr($data,8,1);

$headerlen = 10;

$extralen = 0;

$extra = "";

if ($flags & 4) {

// 2-byte length prefixed EXTRA data in header

if ($len - $headerlen - 2 < 8) {

return false; // Invalid format

}

$extralen = unpack("v",substr($data,8,2));

$extralen = $extralen[1];

if ($len - $headerlen - 2 - $extralen < 8) {

return false; // Invalid format

}

$extra = substr($data,10,$extralen);

$headerlen += 2 + $extralen;

}

$filenamelen = 0;

$filename = "";

if ($flags & 8) {

// C-style string file NAME data in header

if ($len - $headerlen - 1 < 8) {

return false; // Invalid format

}

$filenamelen = strpos(substr($data,8+$extralen),chr(0));

if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {

return false; // Invalid format

}

$filename = substr($data,$headerlen,$filenamelen);

$headerlen += $filenamelen + 1;

}

$commentlen = 0;

$comment = "";

if ($flags & 16) {

// C-style string COMMENT data in header

if ($len - $headerlen - 1 < 8) {

return false; // Invalid format

}

$commentlen = strpos(substr($data,8+$extralen+$filenamelen),chr(0));

if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {

return false; // Invalid header format

}

$comment = substr($data,$headerlen,$commentlen);

$headerlen += $commentlen + 1;

}

$headercrc = "";

if ($flags & 1) {

// 2-bytes (lowest order) of CRC32 on header present

if ($len - $headerlen - 2 < 8) {

return false; // Invalid format

}

$calccrc = crc32(substr($data,0,$headerlen)) & 0xffff;

$headercrc = unpack("v", substr($data,$headerlen,2));

$headercrc = $headercrc[1];

if ($headercrc != $calccrc) {

return false; // Bad header CRC

}

$headerlen += 2;

}

// GZIP FOOTER - These be negative due to PHP's limitations

$datacrc = unpack("V",substr($data,-8,4));

$datacrc = $datacrc[1];

$isize = unpack("V",substr($data,-4));

$isize = $isize[1];

// Perform the decompression:

$bodylen = $len-$headerlen-8;

if ($bodylen < 1) {

// This should never happen - IMPLEMENTATION BUG!

return null;

}

$body = substr($data,$headerlen,$bodylen);

$data = "";

if ($bodylen > 0) {

switch ($method) {

case 8:

// Currently the only supported compression method:

$data = gzinflate($body);

break;

default:

// Unknown compression method

return false;

}

} else {

// I'm not sure if zero-byte body content is allowed.

// Allow it for now... Do nothing...

}

// Verifiy decompressed size and CRC32:

// NOTE: This may fail with large data sizes depending on how

// PHP's integer limitations affect strlen() since $isize

// may be negative for large sizes.

if ($isize != strlen($data) || crc32($data) != $datacrc) {

// Bad format! Length or CRC doesn't match!

return false;

}

return $data;

}

使用:

复制代码 代码如下:

$html=file_get_contents('http://www.jb51.net/');

$html=gzdecode($html);

就介绍这三个方法,应该能解决大部分gzip引起的抓取乱码问题了。

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