Follow Debian guidelines for launching editors

[maxnordlund]

This is how most other tools work when they want the user to edit a file.

[Lockszmith-GH]

Thanks for implementing this, tested and works.

[maxnordlund]

I missed that issue, and VISUAL. So I've included that as well (and squashed the commits while I was at it).

It's not strictly correct though, as it doesn't check if VISUAL or EDITOR points to an executable file. But I figure if someone sets EDITOR they probably know what they are doing 😄

[Lockszmith-GH]

thanks @maxnordlund, obviously, still works - just tested it.

Just a reminder that /usr/bin/editor in debian by default points to nano, so editor instead of nano makes the solution completly in compliance of debain's guidelines. (allowing for system-wide defaults to be changed with update-alternatives)

[Jip-Hop]

If we want to be really complete then we need to check if the command exists too. I think a get_text_editor method would make sense instead of the current global variable. It could loop over VISUAL and EDITOR and check each time if it is a command using shutil.which and return this string if it is a valid command. If neither VISUAL and EDITOR have returned then return /usr/bin/editor.

This has the added benefit of making this bit redundant:

jailmaker/jlmkr.py

Lines 1509 to 1514 in 4867555

	if not shutil.which(TEXT_EDITOR):
	eprint(
	f"Unable to edit config file: {jail_config_path}.",
	f"\nThe {TEXT_EDITOR} text editor is not available",
	)
	return 1

[maxnordlund]

OK, so I took the time to do this properly. It now closely follows the Debian guidelines, including both looking up editor before falling back to /usr/bin/editor, and if all else fails falls back to the old hardcoded nano.