How to use arguments from previous command?
I know that Esc + . gives you the last argument of the last command.
But I'm interested in first argument of开发者_运维知识库 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
, $1
etc., but these don't work on the commandline.
Also, what about iterating through the 0th argument of previous commands, like we can do with the last argument by continuously pressing Esc + .?
!$
gets the last element of the previous command line argument.
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.
To use the first argument, you can use !^
or !:1
Example:
$ echo a b c d e
a b c d e
$ echo !^
echo a
a
$ echo a b c d e
a b c d e
$ echo !:1
echo a
a
Since your question is about using any other arguments, here are some useful ones:
!^ first argument
!$ last argument
!* all arguments
!:2 second argument
!:2-3 second to third arguments
!:2-$ second to last arguments
!:2* second to last arguments
!:2- second to next to last arguments
!:0 the command
!! repeat the previous line
The first four forms are more often used. The form !:2-
is somewhat counter-intuitive, as it doesn't include the last argument.
I liked @larsmans answer so much I had to learn more. Adding this answer to help others find the man page section and know what to google for:
$ man -P 'less -p ^HISTORY\ EXPANSION' bash
<...>
Word Designators
Word designators are used to select desired words from the event.
A : separates the event specification from the word designator.
It may be omitted if the word designator begins with a ^, $, *, -,
or %. Words are numbered from the beginning of the line, with the
first word being denoted by 0 (zero). Words are inserted into the
current line separated by single spaces.
0 (zero)
The zeroth word. For the shell, this is the command word.
n The nth word.
^ The first argument. That is, word 1.
$ The last argument.
% The word matched by the most recent ‘?string?’ search.
x-y A range of words; ‘-y’ abbreviates ‘0-y’.
* All of the words but the zeroth.
This is a synonym for ‘1-$’.
It is not an error to use * if there is just one word in
the event; the empty string is returned in that case.
x* Abbreviates x-$.
x- Abbreviates x-$ like x*, but omits the last word.
If a word designator is supplied without an event
specification, the previous command is used as the event.
Tested on Ubuntu 18.04
To insert previous arguments:
- Alt+.: insert last argument from last command.
- Alt+#+.: insert #nth last argument from last command.
- Alt+- , # , Alt+., zsh: Alt+-+#+.: insert #nth first argument from last command.
In Linux you can repeat commands to go back in history
Example:
Last command is:
mv foo bar
- Alt+0+.: insert first argument of last command =
mv
- Alt+2+.: insert last 2nd argument of last command =
foo
- up , Ctrl+w: last command without the last word =
mv foo
General shortcuts
- Ctrl+w: removes last word from cursor
- Alt+d: removes next word from cursor
- Ctrl+k: cuts everything after cursor
- Ctrl+u, zsh: Alt+w: cuts everything before cursor
- zsh: Ctrl+u: cuts the entire command (In bash you can combine Ctrl+u , Ctrl+k)
- Ctrl+y: paste characters previously cut with Ctrl+u and Ctrl+k
- Ctrl+_: undo last edit (very useful when exceeding Ctrl+w)
- Ctrl+left: move to last word
- Ctrl+right: move to next word
- home or Ctrl+a: move to start of line
- end or Ctrl+e: move to end of line
To iterate through the arguments in a previous command
only works in zsh
run or add this to your ~/.zshrc
autoload -Uz copy-earlier-word
zle -N copy-earlier-word
bindkey "^[:" copy-earlier-word
Now use Alt+. to go as back as you want, then use Alt+: to iterate through the arguments
Assuming last command is
echo 1 2 3 4 5
- Alt+.:
5
- Alt+.+::
4
- Alt+.+:+::
3
- Alt+.+:+:+::
2
- Alt+.+:+:+:+::
1
- Alt+.+:+:+:+:+::
echo
source: https://stackoverflow.com/a/34861762/3163120
To see all shortcuts available
- bash:
bind -lp
- zsh:
bindkey -L
I'm keeping this up-to-date here: https://github.com/madacol/knowledge/blob/master/bash-zsh_TerminalShorcuts.md
!^ may be the command for the first argument. i'm not sure if there is a way to get the nth.
You can also get arguments from any command in your history!
$ echo a b c d e f g
a b c d e f g
$ echo build/libs/jenkins-utils-all-0.1.jar
build/libs/jenkins-utils-all-0.1.jar
$ history | tail -5
601 echo build/libs/jenkins-utils-all-0.1.jar
602 history | tail -10
603 echo a b c d e f g
604 echo build/libs/jenkins-utils-all-0.1.jar
605 history | tail -5
$ echo !-3:4
echo d
d
$ echo !604:1
echo build/libs/jenkins-utils-all-0.1.jar
build/libs/jenkins-utils-all-0.1.jar
!^ will get you the first param, !$ will get you the last param, !:n will get you the nth element.
Basically it has a use in yanking previous (command's) arguments.
For instance, if the following command is issued:
echo Hello, world how are you today?
then, Hello,
will be the first argument, and today?
the sixth, that is the last one; meaning it can be referenced by typing:
Alt+6 followed by Ctrl-Alt-6
Ctrl is traditionally denoted as a hat character ^
prepended to keys names, and Alt as M-
that is Meta prefix.
So the above shortcut can be redefined as ^My
to yank.
Also, there is hats substitution shortcut in the command line:
echo Hello, world!
^Hello^Bye
Bye, world!
to substitute the previous command's first matched string, meaning:
Hello, world! Hello, people!
^Hello^Bye
would result in:
Bye, world! Hello, people!
leaving the second match (hello
) unchanged.
Note: Do not leave space between hats, or the operation won't work.
The above is just a shortcut for:
!:s/Hello/Bye
event-level(*) substitution for the first found (matched) string in the previous command, while prefixing the first part with the g
switch will apply to the whole line globally:
echo Hello, world! Hello, people!
!:gs/Hello/Bye
Bye, world! Bye, people!
as usually being done in other related commands such as sed
, vi
, and in regex
(regular expression) - a standart way to search (match string).
No, you can't do
!:sg/Hello/Bye
or!:s/Hello/Bye/g
here, that's the syntax!
- ! is for events; event might be understood as command output or operation done in the commands history.
That's what I understood by using it myself and trying things on my own from what I read from various sources including manual pages, blogs, and forums.
Hope it will shed some light into mysterious ways of bash
, the Bourne-Again shell (a play on sh
shell, which itself is called Bourne shell after its inventor's last name), what is default shell in many distributions including servers (server OS's).
The method described at the end of the accepted answer also works with the zeroth argument for me. I have these lines in my ~/.inputrc
:
"\en": "\e0\e."
"\em": "\e1\e."
"\e,": "\e2\e."
\e2\e.
has the advantage over \e2\e\C-y
that it cycles through previous commands if it is pressed repeatedly instead of inserting the second argument of the previous command multiple times.
To insert the whole previous command, you can type !!\e^
. \e^
is history-expand-line
.
If you are on a mac you will tend to get extended characters with ctrl+letter. I have my right-of-space-bar-option key defined as meta in my terminal (iTerm2) set up. This means I use the key to navigate by word and pull parameters from previous commands.
For pasting 1th argument, press and hold down Alt key, and while it is down, hit the '1' key followed by the '.' key.
For pasting n-th argument, replace the '1' key above with the corresponding number key.
If this does not work, your terminal emulator may be catching the Alt key before it gets to shell. Some terminals (xfce4-terminal) allow turning off the "Alt-" shortcuts in the configuration file.
Credit to Jonas Eberle, I've fished this out from his comment to another answer here.
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