Posted by refp 5 days ago
Same with Ctrl-C - once I got used to navigating by word instead of by character to correct things, it became much faster than starting over.
As suggested in the FAQ at the bottom, instead of !… you can use ctrl-r. Or better, optionally type the first letters then alt-p or "up". It's more powerful and more extensible. Other shortcuts, like alt-., allow navigating into the past parameters.
With up, alt-p, alt-. and such, the command line displays the real command. The !… magic is more error-prone and ambiguous; with zsh, I'd suggest hitting TAB to expand the magic into a static text.
I would add other entries to the FAQ: When I enter `sudo !!` will it be stored unchanged in the shell history, or stored after interpolation of `!!`? When I start a command line with a space, so that zsh does not put it in the shell history, will !… also ignore that line? Is `!$` recursive?
P.S. The alt+s shortcut is much quicker than writing sudo !!
This also adds an intriguing new dimensions to reviewing/verifying shell commands as benign and correct... How long until LLMs start (ab)using the trick in little requests they want me to approve?
There's enough complexity in the language spec that most people stick with a (fairly shared) subset.
Bash can be very powerful, but IMHO there's a certain point where I find it saner to accomplish the same thing via Python.
!! is handy for the sudo example, but beyond that, I tend to prefer pressing the up arrow to cycle through the history rather than picking the first item. Eg:
!ssh
ssh[up]
> I've been burnt before using ! and forgetting what command I typed previously
If you want to make sure you do not execute commands you did not intend to, the section linked below is a great start:
- https://refp.se/articles/your-shell-and-the-lazy-exclamation...
You may also look into `magic-space` which makes the expansion of event-designators happen inline, I thought about including it but the article felt long even without it.
Thanks for reading the article, I hope it was a worthwhile read even with alternate workflows elsewhere!
bind space:magic-spaceAnd yeah, I've done editing with ed; it definitely beats "cat >file.txt" and copying parts around with head/tail and retyping the corrections manually, sure, and it works in every environment that can take line-oriented input from the user (so, literally everywhere), but that's about as much praise as I can give it.
From personal experience I rarely reach for event-designators beyond the current viewport of the terminal. Referring to a command beyond that is, as you very much correctly point out, an easy way to get behavior you don't want. However, if you are always referring to things that are near-memory or even still directly visible in your terminal buffer — the gun-to-foot ratio becomes manageable. I use many (many) of these daily without issues, but it does require some additional discipline.
Also, and this I find important to note, `!!` and `!$` sit outside of the memory argument as they always refer to the last command and last-command's last-argument respectively — as such there shouldn't be any recall related problems (unless you are context switching and come back to a shell in a state you don't remember).
A common occurrence when my posts acquire attention is that I retroactively realize that some things could have been conveyed better; I read every comment and yours is a blessing in disguise to improve future writing.
Thanks for reading the article, and thanks for indirectly making me a better writer!
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EDIT:
by the way, for what it's worth, the below linked section describes how to effectively explicitly confirm what you would run as a safety measure if unsure:
https://refp.se/articles/your-shell-and-the-lazy-exclamation...
!-2 && !!
Right, as a matter of (relatively trivial) cybernetics between man and machine, it rests on the weaker parts of the human.
TBF, it'd make a lot more sense if every command on screen (or given the timescale perhaps teletype paper prinout) was already labeled with the necessary number.
PS1="(\\!) \[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ "
as a full working example
trying to write shell commands on a hypervisor console window within a remote session on a jump box is excruciatingly laggy and annoying, and that's assuming your remote session connection to the client is behaving well in the first place
I'm way too paranoid to ever use "!". I want to see the command I'm sending.
and yeah ^r works, though i often type a few chars and ^p till i get the match. history-search-backward in your inputrc, iirc
edit: on a computer now :) my `if emacs` block, allowing arrows or ^n/^p to run through history. so for e.g., type "tar" and now as you shift through history with :binding:, it only shows history that began with "tar"
$if mode=emacs
"\e[A": history-search-backward
"\e[B": history-search-forward
"\C-p": history-search-backward
"\C-n": history-search-forward
...
$endif``` mkcd() { mkdir -p -- "$*" && cd -- "$*" } ```