Every time someone brings this up, I think "oh right, I could do that" and then immediately forget. Especially if you can type quickly, it's easier to just "drive straight ahead" with the command you want, than add another "mental branch" to interrupt the flow. For the same reason I'll often Ctrl+C and start again instead of trying to backspace and correct.
adityaathalye 1 hours ago [-]
As an Emacs using degenerate, `M-.` is my friend. `!` is too awkward on the keyboard.
hnlmorg 42 minutes ago [-]
I’ve been burnt before using ! and forgetting what command I typed previously, thus invoking the wrong command line.
!! 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
vs
ssh[up]
It’s the same number of key strokes but less error prone
CoastalCoder 28 minutes ago [-]
Agreed. I especially cringed at the author's example of mixing that with "sudo".
refp 24 minutes ago [-]
the "mixing of sudo"-example is using `!!`, which as explained is the immediately previous command, a little confused how that translates to the "execute command somewhere in the history" argument?
Terr_ 3 hours ago [-]
Rather than a sense of "cool" or "useful" somehow I end up just feeling despair at how organically convoluted it is to determine what something on a command-line really does. To be fair, I've always been biased towards "only the simplest scripts should be in shell languages."
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?
CoastalCoder 30 minutes ago [-]
Maybe it's a bit like current C++ language spec:
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.
magarnicle 40 minutes ago [-]
man bash. That's the secret. man bash.
csydas 2 hours ago [-]
! calls are vital for your sanity if you ever do remote support
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
crabbone 1 hours ago [-]
I have a script that does virsh send-key of whatever I need to send. In my specific case the motivation was the mismatch between my keyboard layout and the keyboard in the VMs, so I couldn't send M-# or even C-... into the VNC console.
I'm way too paranoid to ever use "!". I want to see the command I'm sending.
Joker_vD 3 hours ago [-]
sigh The usability of ! versus Ctrl+R in a shell is pretty much the same as the usability of ed versus vi, or moving files around using cp/mv versus using Midnight Commander or the like: in the first case, you have to accurately remember the past (which for many people is pretty difficult); in the second case, you don't have to, because you always have an immediate view of the state of the system and the preview of the effect you're about to incur.
And 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.
refp 12 minutes ago [-]
> you have to accurately remember the past
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 `!$` sit outside of the memory argument as they always refer to the last command and last-command's last-argument respectively — as such there shouldn't be any recall related problems (unless you are context switching and come back to a shell in a state you don't remember).
A common occurrence when my posts acquire attention is that I retroactively realize that some things could have been conveyed better; I read every comment and yours is a blessing in disguise to improve future writing.
Thanks for reading the article, and thanks for indirectly making me a better writer!
Terr_ 3 hours ago [-]
> in the first case, you have to accurately remember the past
Right, as a matter of (relatively trivial) cybernetics between man and machine, it rests on the weaker parts of the human.
TBF, it'd make a lot more sense if every command on screen (or given the timescale perhaps teletype paper prinout) was already labeled with the necessary number.
petschge 2 hours ago [-]
You can just add something like (\\!) in your PS1 and get just that.
i love the mkdir example, so i’m going to exercise that muscle and see where it goes
and yeah ^r works, though i often type a few chars and ^p till i get the match. history-search-backward in your inputrc, iirc
edit: on a computer now :) my `if emacs` block, allowing arrows or ^n/^p to run through history. so for e.g., type "tar" and now as you shift through history with :binding:, it only shows history that began with "tar"
That one was always worth its own function for me.
```
mkcd() {
mkdir -p -- "$*" && cd -- "$*"
}
```
rixed 2 hours ago [-]
If you find this interesting, don't wait for a random blogpost to appear by chance on HN, go read some manage today!
b112 2 hours ago [-]
Everyone need be aware, bash uses emac extensions by default. As I refuse to use emacs, I therefore refuse to use these extensions in bash!
In as most sensible people use vi, don't taint yourself by touching this foul and evil emacs magic. Being known as an emacs user could cost you a job, shorten your career, or even cause
rifts with family and friends.
Instead my friends, if you must use such bash shenanigans, switch it to vi extensions. You'll feel better about yourself, stand taller, and be a better human being as a result.
Be safe.
adityaathalye 1 hours ago [-]
Well, Emacs shenanigans are why I use Bash. Also, I last had a day job five years ago, I don't have anything that looks like a career, and well you're right about some of the family and friends.
You are a soothsayer!
charcircuit 42 minutes ago [-]
Not knowing what command you are doing before you submit it is poor design. There are alternative ways to access old commands where you can see the actual command you are about to run before you submit it. The physical teletype era is over.
RMPR 3 hours ago [-]
If you really want to be lazy, use a terminal file manager (I prefer lf[0]) it helps avoiding the cd && ls dance. That way, your history only contains commands you actually would want to rerun.
!! 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:
vs It’s the same number of key strokes but less error proneThis 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.
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, 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!
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
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"
``` mkcd() { mkdir -p -- "$*" && cd -- "$*" } ```
In as most sensible people use vi, don't taint yourself by touching this foul and evil emacs magic. Being known as an emacs user could cost you a job, shorten your career, or even cause rifts with family and friends.
Instead my friends, if you must use such bash shenanigans, switch it to vi extensions. You'll feel better about yourself, stand taller, and be a better human being as a result.
Be safe.
You are a soothsayer!
0: https://github.com/gokcehan/lf
just turn on the thing where a leading space doesn't commit to history and you can do this already.