Ruby 3 IRB home end and ctrl-u not working

Question

I've recently started using Ruby 3 more and it seems the home key (to take me to the beginning of the line) the end key (end of the line) and ctrl-u (clear the line) aren't working.

I'm running Arch Linux with Ruby 3.1.1p18 and a zsh shell. The keys work fine on Ruby 2.7. I've tried with Alacritty and xfce4-terminal and both have the same issue. I'm not using Tmux or anything similar.

There is this similar question from a few years ago but that's for Windows and the solutions didn't help: Backspace and arrow keys aren't working in IRB(Git Bash console) on windows machine

Xylography

This is most likely an issue with your terminal bindings, not IRB. Check your TERM variable and any vi, emacs, or readline bindings for your shell. – Dragone

Thanks @ToddA.Jacobs, when I don't have x launched it seems the home and end keys work but ctrl-u does not. When I launch X they don't work. I've tried clearing my zshrc, changing my TERM from xterm-256color to linux (which is what it is before launching x) as well as switching to bash and trying a different terminal emulator. No matter what I try, when X is running non of the keys work and instead I get a few strange characters printing – Xylography

This solution worked - github.com/ruby/irb/issues/330#issuecomment-1132017233 – Weltschmerz

Answer 1

I have found a good solution for this issue in this Archlinux guide: Home_and_End_keys_not_working

Just create the file ~/.inputrc with the content:

"\e[1~": beginning-of-line
"\e[4~": end-of-line
"\e[7~": beginning-of-line
"\e[8~": end-of-line
"\eOH": beginning-of-line
"\eOF": end-of-line
"\e[H": beginning-of-line
"\e[F": end-of-line

This solution works pretty good for me.

Remorseful

Oh wow, almost exactly a year after I asked the question you solved my issue with just a simple config file :) Thanks! – Xylography

Answer 2

I also specifically see ctrl-u not working in Ruby 3's irb, despite other ctrl commands working (ctrl-a, ctrl-k).

For the meantime, I'm using pry for my REPL. Bonus… I prefer it's simpler auto-complete.

gem install pry
pry

Pinkard

Answer 3

I can't take credit for this as this is just a copy from: https://github.com/ruby/irb/issues/330, but I hope this is useful for those that stumbled upon this question without a good answer.

For those who would prefer to do the above patches at runtime, for macOS/iTerm2, add this code to "~/.irbrc":

require "reline/ansi"

if defined?(Reline::ANSI::CAPNAME_KEY_BINDINGS) # make sure you're using an affected version
  # Fix insert, delete, pgup, and pgdown.
  Reline::ANSI::CAPNAME_KEY_BINDINGS.merge!({
    "kich1" => :ed_ignore,
    "kdch1" => :key_delete,
    "kpp" => :ed_ignore,
    "knp" => :ed_ignore
  })

  Reline::ANSI.singleton_class.prepend(
    Module.new do
      def set_default_key_bindings(config)
        # Fix home and end.
        set_default_key_bindings_comprehensive_list(config)
        # Fix iTerm2 insert.
        key = [239, 157, 134]
        func = :ed_ignore
        config.add_default_key_binding_by_keymap(:emacs, key, func)
        config.add_default_key_binding_by_keymap(:vi_insert, key, func)
        config.add_default_key_binding_by_keymap(:vi_command, key, func)
        # The rest of the behavior.
        super
      end
    end
  )
end

No switch to application mode needed, and no iTerm2 rebinding.

Repartition

Answer 4

This was fixed in a newer version of reline, but in the meantime what you can do is add this to your ~/.irbrc:

Reline::KeyActor::Emacs::MAPPING[21] = :unix_line_discard

Heterologous