php实现不通过扩展名准确判断文件类型的方法【finfo_file方法与二进制流】

$handle=finfo_open(FILEINFO_MIME_TYPE);//This function opens a magic database and returns its resource. $fileInfo=finfo_file($handle,'./test.txt');// Return information about a filefinfo_close($handle);print_r($fileInfo);echo '==========="/n"';

$fp=fopen('test.txt','r')///实际是image/png$bin = fread($fp, 2); //只读2字节fclose($fp);$str_info = @unpack(“C2chars”, $bin);//Unpack data from binary string$type_code = intval($str_info['chars1'].$str_info['chars2']);// Get the integer value of a variable$file_type = ”;switch ($type_code) {case 7790:$file_type = 'exe';break;case 7784:$file_type = 'midi';break;case 8075:$file_type = 'zip';break;case 8297:$file_type = 'rar';break;case 255216:$file_type = 'jpg';break;case 7173:$file_type = 'gif';break;case 6677:$file_type = 'bmp';break;case 13780:$file_type = 'png';break;default:$file_type = 'unknown';break;}