如何在GNU nano中启用撤销功能？含2.3.1版本及SSH场景方案

Hey there! Let's break down your nano questions clearly, since you can't update the installed version on your server right now.

Short answer: Yes, it does! The undo/redo feature was added well before the 2.3.1 release, so your version definitely includes it. The catch is that it might not be enabled by default, and you might not know the right shortcuts to use it.

You have two main options to get undo working on your current version:

1. Enable temporarily for a single session #

When you launch nano via SSH, just add the -u flag to the command. For example:

nano -u your-file.txt

Once the file is open, you can use these shortcuts:

• Undo: Press Alt+U (if your terminal maps Alt to Esc, use Esc+U instead — this is common in many SSH clients like PuTTY or macOS Terminal)
• Redo: Press Alt+E (or Esc+E if Alt is mapped to Esc)

2. Enable permanently for all your sessions #

If you don't want to type the -u flag every time, you can set this as your default by editing your user-specific nano config:

1. First, check if you already have a ~/.nanorc file. If not, create it with this command:

   touch ~/.nanorc
   

2. Open the file with nano (feel free to use the temporary undo flag here!):

   nano -u ~/.nanorc
   

3. Add this single line to the file:

   set undo
   

4. Save and exit (Ctrl+O, then Enter, then Ctrl+X). From now on, every time you open nano, undo/redo will be enabled by default.

A quick note: Some servers have a system-wide config at /etc/nanorc, but editing your personal ~/.nanorc is safer because it won't affect other users on the server.

内容的提问来源于stack exchange，提问作者saeed mohammadi