linux nano中为什么M代表[Alt],^代表[Ctrl]?

Question

nano中最后两行选项中有很多组合键,比如按[Ctrl]-O后会见到M-D,M-M这样的形式,这里的M代表[Alt],为啥?我想肯定是有道理的,不然为啥不用A-D,A-M这样表示呢?另外M有时候也代表Meta键或Menu键,这样不就混淆了吗?还有为什么^C中的^代表[Ctrl]?为什么不是C-C?

Answer 1

When you see M, you usually think of Meta. It seems that under Mac, it is Meta, and under Linux, it corresponds to Alt.
I haven't looked up the specific meaning.

The shortcut keys written next to the menu on Mac are all ^, which should represent Ctrl, as well as ⌥ (Alt) ⌘ (Command) and Shift similar to ⌂ (cannot be typed).