程式師世界 >> 編程語言 >> 網頁編程 >> PHP編程 >> 關於PHP編程 >> php file_get_contents抓取Gzip網頁亂碼的三種解決方法

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

編輯：關於PHP編程

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？獲取的頭部當中有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查看我的博客的頭信息，Gzip是開了的。
復制代碼代碼如下:
請求頭信息原始頭信息
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.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

下面介紹一些解決方案：

1. 使用自帶的zlib庫
如果服務器已經裝了zlib庫，用下面的代碼可以輕易解決亂碼問題。
復制代碼代碼如下:
$data = file_get_contents("compress.zlib://".$url);

2. 使用CURL代替file_get_contents
復制代碼代碼如下:
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"); // 關鍵在這裡
$content = curl_exec($curl);
curl_close($curl);
return $content;
}

3. 使用gzip解壓函數
復制代碼代碼如下:
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：
復制代碼代碼如下:
$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。