php file_get_contents抓取Gzip網頁亂碼的三種解決方案

用 file_get_contents() 函數抓取網頁會發生亂碼現象。有兩個原因會導致亂碼，一個是編碼問題，一個是目標頁面開了Gzip，下面說的就是開了Gzip功能如何才能不亂碼的方法

把抓取到的內容轉下編碼即可($content=iconv("GBK", "UTF-8//IGNORE", $content);)，我們這裡討論的是如何抓取開了Gzip的頁面。怎麼判斷呢？擷取的頭部當中有Content-Encoding: gzip說明內容是GZIP壓縮的。用FireBug看一下就知道頁面開了gzip沒有。下面是用firebug查看我的部落格的頭資訊，Gzip是開了的。
要求標頭資訊原始頭資訊

Accept text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8Accept-Encoding gzip, deflateAccept-Language zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3Connection keep-aliveCookie __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=225240837.1.10.1335411401Host www.nowamagic.netUser-Agent Mozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20100101 Firefox/12.0

下面介紹一些解決方案：

1. 使用內建的zlib庫
如果伺服器已經裝了zlib庫，用下面的代碼可以輕易解決亂碼問題。

$data = file_get_contents("compress.zlib://".$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"); // 關鍵在這裡 $content = curl_exec($curl); curl_close($curl); return $content;}

3. 使用gzip解壓函數

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：

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

就介紹這三個方法，應該能解決大部分gzip引起的抓取亂碼問題了。

