[Linux] 判斷未知的分割區格式

今天撿到一張記憶卡，想要看看裡面是什麼東西，結果一直 mount 不起來，錯誤訊息

NTFS signature is missing.
Failed to mount '/dev/mmcblk0p2': Invalid argument
The device '/dev/mmcblk0p2' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

後來看到這篇，用這個指令就可以知道這是什麼格式了

sudo file -s /dev/mmcblk0p2