I am using vi mode in a bash shell.
If I enter
insert command mode and type a number from 1-9 (eg: 5, in the example below), I get the following prompt:
(arg: 5) <cursor>
What does this mean? I can't seem to do anything useful with this prompt, and I don't know what its purpose is.
I even poked into the bash sources, which in turn gets into the GNU Readline sources.
The function that ends up being called is
rl_vi_arg_digit, which then calls
rl_digit_argument, which displays the
(arg: N) prompt. But I can't see from comments or related code what it's actually used for.