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Three solutions to php file_get_contents grabbing garbled Gzip web pages_PHP tutorial

WBOY
WBOYOriginal
2016-07-13 10:25:211188browse

Just convert the captured content to encoding ($content=iconv("GBK", "UTF-8//IGNORE", $content);). What we are discussing here is how to capture and open Gzip page. How to judge? The obtained header contains Content-Encoding: gzip indicating that the content is GZIP compressed. Use FireBug to check whether gzip is enabled on the page. The following is the header information of my blog viewed using firebug. Gzip is turned on.

Copy code The code is as follows:

Request header information original header information
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.nowamagic.net; PHPSESSID=888mj4425p8s0m7s0frre3ovc7; __utmc=225240837; __utmb=225240837.1.10.1335411401
Host www.nowamagic .net
User-Agent Mozilla /5.0 (Windows NT 5.1; rv:12.0) Gecko/20100101 Firefox/12.0

Here are some solutions:

1. Use the built-in zlib library
If the server has installed the zlib library, you can easily solve the garbled code problem by using the following code.

Copy code The code is as follows:

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

2. Use CURL instead of file_get_contents

Copy the code The code is as follows:

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"); // The key is here
$content = curl_exec($curl);
curl_close($curl);
return $content;
}

3. Use gzip decompression function

Copy code The code is as follows:

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;
}


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。

www.bkjia.comtruehttp://www.bkjia.com/PHPjc/825112.htmlTechArticle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...
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