If your workflow is populated with a lot of repetitive actions, then it never hurts to look for ways to improve and streamline your workflow. Today’s SuperUser Q&A post has some helpful suggestions for a reader seeking to improve his workflow.
Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.
Screenshot courtesy of Matt Joyce (Flickr).
SuperUser reader coin wants to know how to quickly change the first word in a bash command:
I would like to improve my workflow in bash and realized that I often want to execute the same command to a different executable.
I know that I can hit Ctrl+a then Del to remove the first word, but I am wondering if there is a quicker way to do it.
Is there a quicker way for coin to change the first word in bash commands?
SuperUser contributors Spiff, Hastur, jjlin. and Gustavo Giraldez have the answer for us. First up, Spiff:
!$ expands to the last word of your previous command. So you could do:
Your examples happened to only repeat the last word, so !$ worked fine. If you actually had a lot of arguments that you wanted to repeat, and you just wanted to change the first word, you could use !*, which expands to all words of the previous command except the zeroth.
See the “HISTORY EXPANSION” section of the bash man page. There is a lot of flexibility there.
Followed by the answer from Hastur:
I would like to add a warning (see the answer from Spiff above). With !$, you do not have full visual control of the line you are running. The results can be harmful sometimes, especially if you incur a misprint. It takes what it needs from the history to expand on.
So if you write the last command with a blank space at the beginning, then this command will probably not finish from the history. When you execute your new command with !$, the shell will not take the parameters from the last command line typed, but only from the last part of the history.
Here are some more helpful words and commands.
Then the answer from jjlin:
Ctrl+a to go to the beginning of the line, then Alt+d to delete the first word.
And our final answer from Gustavo Giraldez:
The delete word shortcut is actually Meta+d, and Meta is usually mapped to Alt on Linux machines. On platforms where this is not the case, an alternative to get the Meta modifier is to use Esc as a prefix. You can read more about the Meta Key here.
Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.