Linux - How to edit a file?

To edit a file in the shell mode, you have to use an editor such as:

• emacs
• vi
• pico
• gedit
• nano

To edit the file:

  emacs file.txt
  vi file.txt
  pico file.txt

To save the file:

• with pico type CTRL+O to save and CTRL+X to exit.
• with vi, see this article: Text Editor - Vi (VIM)
• with emacs: Ctl-x Ctl-c