php file_get_contents抓取Gzip网页乱码的三种解决方法

发布:smiling　来源: PHP粉丝网　添加日期：2020-06-23 16:24:59　浏览: 评论：0　

用 file_get_contents() 函数抓取网页会发生乱码现象。有两个原因会导致乱码，一个是编码问题，一个是目标页面开了Gzip，下面说的就是开了Gzip功能如何才能不乱码的方法。

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。

请求头信息原始头信息。

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

Accept-Encoding gzip, deflate

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

Connection keep-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.phpfensi.com; PHPSESSID=888mj4425p8s0m7s0frre3ovc7; __utmc=225240837; __utmb=225240837.1.10.1335411401

Host www.phpfensi.com

User-Agent Mozilla/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。

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

2. 使用CURL代替file_get_contents

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:

function gzdecode($data) {

  $len = strlen($data);

  if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) {

    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;

}