How to set visudo to use a different editor than the default on Fedora?

A normal unix program that wants to invoke an editor will run the program whose name is in the EDITOR or VISUAL environment variable, and if the variable is unset, a system-dependent default. Many, but not all, programs check both EDITOR and VISUAL; the distinction is long obsolete (once you would run EDITOR on a teletype and VISUAL on a “glass” terminal…) so you should set both to the same value. There is some disagreement as to whether the contents of the variable should be the full path to an executable, an executable name that’s looked up in $PATH, or a shell snippet, so you should stick to a path to an executable not containing any shell metacharacter. The system default when neither variable is set is traditionally vi, though some distributions have changed this to a more newbie-friendly editor such as nano.

visudo checks both VISUAL and EDITOR (this can be compiled out, presumably to dissuade root from using an editor whose security the distribution maker doesn’t trust, but even OpenBSD doesn’t do this).

These steps let me set the editor to vi for visudo on Ubuntu 12.04, they may work for other distributions:

Issue command:

sudo visudo

This opens up the sudoers file in nano. Near the top you will see this line:

Defaults    env_reset

Add the following line beneath the above line:

Defaults    editor=/usr/bin/vi

Save the file and exit. Reopen visudo as your default user:

sudo visudo

The sudoers file now opens up in VI.

The following

• works for distros that use alternatives (originally just Debian and its forks, but now most major distros, IIUC).

• has the advantage that

  1. you won’t need to edit sudoers first with its default editor
  2. it works even if package=sudo has not been built with --with-env-editor

From a commandline:

1. Run sudo update-alternatives --config editor
2. Choose desired editor from the (text-mode) menu. If you don’t see the editor you want, you probably need to install it; cancel, do that, and repeat.

sudo visudo should now open the editor of your choice.

visudo uses the EDITOR variable, for example.

sudo EDITOR=/path/to/editor visudo

IMPO the best way to do this is to have each user set their own preferred editor using the EDITOR and VISUAL environment variables in their own .bashrc file (or the equivalent for their preferred shell), then tell sudo to respect those variables.

So you would add this to /etc/sudoer using visudo:

## Respect the user's choice of editors
Defaults env_keep += "EDITOR VISUAL"

Then add this to ~/.bashrc:

# e.g. if you want to use micro
EDITOR=micro
VISUAL=micro

For the distinction between EDITOR and VISUAL and why I think it’s best to set both, see this answer.

After this sudo visudo should use the user’s preferred editor for all users.