PHP读gzip内容，不需要写到文件

#PHP读gzip流

if (!function_exists('gzdecode')) { 

function gzdecode ($data) { 

$flags = ord(substr($data, 3, 1)); 

$headerlen = 10; 

$extralen = 0; 

$filenamelen = 0; 

if ($flags & 4) { 

$extralen = unpack('v' ,substr($data, 10, 2)); 

$extralen = $extralen[1]; 

$headerlen += 2 + $extralen; 

} 

if ($flags & 8) // Filename 

$headerlen = strpos($data, chr(0), $headerlen) + 1; 

if ($flags & 16) // Comment 

$headerlen = strpos($data, chr(0), $headerlen) + 1; 

if ($flags & 2) // CRC at end of file 

$headerlen += 2; 

$unpacked = @gzinflate(substr($data, $headerlen)); 

if ($unpacked === FALSE) 

$unpacked = $data; 

return $unpacked; 

} 

}