php 获取文件后缀

  /**
     * 获取文件后缀
　　  * $path 本地存储临时文件路径
     * */
    private function getFileType($path){
        $fp=fopen($path,'r');
        $bin = fread($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;
        }
        return $file_type;
    }