How can I unbind and remap C-w in Bash?

Question

I'd like to map Ctrl-w to kill-region in Bash 4.2. This key is bound to unix-word-rubout (delete word backward) by default. According to the manual, remapping should be possible with the bind command which has the options

-u function Unbind all keys bound to the named function.

-r keyseq Remove any current binding for keyseq.

I tried bind -r "\C-w" and bind -u unix-word-rubout but the key is not unset and, as bind -P | grep unix-word-rubout reveals, there was no change in the mapping.

I played with bind a little and I'm able to unbind other built-in keys but not Ctrl-w.

Answer 1

Ctrl-w is bound in stty to werase. You will need to unbind it there first.

stty werase undef
bind '"\C-w":kill-region'

Answer 2

By default, readline attempts to bind the control characters treated specially by the kernel's terminal driver to their readline equivalents. (To see how your terminal is configured, run

stty -a

.) Your terminal presumably has Ctrl-w set to werase, so bash binds it to unix-word-rubout. This binding takes precedence over any keybindings that you specify in ~/.inputrc.

To avoid this mapping, you need to set the readline variable bind-tty-special-chars to off in your ~/.inputrc file:

set bind-tty-special-chars off