I know that Esc + . gives you the last argument of the last command.
But I'm interested in first argument of the last command. Is there a key binding to do so?
On the same lines, is there a generic way of getting the nth argument from the last command?
I know that in a bash script, you can use $0, $1 etc., but these don't work on the commandline.
Also, what about iterating through the 0th argument of previous commands, like we can do with the last argument by continuously pressing Esc + .?
Just as M-. (meta-dot or esc-dot or alt-dot) is the readline function yank-last-arg, M-C-y (meta-control-y or esc-ctrl-y or ctrl-alt-y) is the readline function yank-nth-arg. Without specifying n, it yanks the first argument of the previous command.
To specify an argument, press Escape and a number or hold Alt and press a number. You can do Alt--to begin specifying a negative number then release Alt and press the digit (this will count from the end of the list of arguments.
Example:
Enter the following command
$ echo a b c d e f g
a b c d e f g
Now at the next prompt, type echo (with a following space), then
Press Alt-Ctrl-y and you'll now see:
$ echo a
without pressing Enter yet, do the following
Press Alt-3 Alt-Ctrl-y
Press Alt-- 2 Alt-Ctrl-y
Now you will see:
$ echo ace
By the way, you could have put the echo on the line by selecting argument 0:
Press Alt-0 Alt-Ctrl-y
Edit:
To answer the question you added to your original:
You can press Alt-0 then repeatedly press Alt-. to step through the previous commands (arg 0). Similarly Alt-- then repeating Alt-. would allow you to step through the previous next-to-last arguments.
If there is no appropriate argument on a particular line in history, the bell will be rung.
If there is a particular combination you use frequently, you can define a macro so one keystroke will perform it. This example will recall the second argument from previous commands by pressing Alt-Shift-Y. You could choose any available keystroke you prefer instead of this one. You can press it repeatedly to step through previous ones.
To try it out, enter the macro at a Bash prompt:
bind '"\eY": "\e2\e."'
To make it persistent, add this line to your ~/.inputrc file:
"\eY": "\e2\e."
Unfortunately, this doesn't seem to work for arg 0 or negative argument numbers.