Look at Carapace for even better completions
TIL
I usually use
--helpas it also gives descriptions for the command, though some programs may only accept-hor no argument to show the help menu.In zsh, you can configure the completion to also show descriptions.
Interesting, I use fish shell and as far as I know it just shows you the options for most programs.
I’d like something like on Cisco equipment.
Tab completes a command
? prints possible options with brief descriptions, filtered by starting letters if you already typed anything
if there is just one option left, you can just use it directly, so you can write shortened commands (similar to ip commands on Linux)That would be the dream indeed. It’s so fluid after you learn it. Other networking equipment often has good configuration CLIs as well (like juniper and vyos), but Cisco is probably the best in my experience. It’s also nice how consistent they are across generations.
You can get about as close as it’s possible in a normal operating system with zsh and plugins like zsh-autocomplete. Bash tries to pick up the possible alternatives from context as well (with tab suggestions) that act somewhat like
?on Cisco CLI, but implementing it is left up to the command itself to provide for the shell. Many commands luckily provide very robust autocompletion to bash out-of-the-box, especially if installed via the system package manager.Unfortunately we’ll probably never reach the point of actual configuration CLIs since they only have a set amount of commands that are developed by the same company. It would be close to impossible to achieve the same level of standardisation for a general operating system, as we don’t know the entire configuration of the system and there are multiple incompatible flag schemes. (As styles go, things like dd and ffmpeg throw a wrench in the works with their non-standard flags)
Whenever someone says they don’t really like terminal because they don’t like to type or remember commands. This is what I think “they didn’t use auto complete”.
Auto complete works for file names and paths by default, but the development can write it to only complete certain extensions. Like auto complete for image program only completes image files. Then you have completion for commands, subcommands and flags.
Auto complete is done through calling a bash script with currently typed line, and the bash script can call other commands. So developer can write a really complicated auto complete and make it available as a binary if they want, and just use that in bash. Or you can use many tools that will generate auto complete script for you based on your commandline args.
If you write your own scripts/cli binaries I recommend learning how to write auto complete for it. Makes it incredibly easy to use the tools.
i was in the dark for so long because i thought tab autocompletions only worked with file paths. i can’t believe that whole time i didn’t even accidentally hit tab once on a command
I guess it can go unnoticed, I use Arch so maybe that’s why I got more involved. I remember searching why auto completion didn’t work, then finding out I need to install bash-completions package. After knowing that it makes one curious about how it works. Then the next stage is writing it for my own programs because it obviously won’t come with bash-completions package.
I once wrote a shell (terminal) to watch anime, and I wrote auto completion for different commands on it, it was really nice to just type
playthen prefix and then tab for auto completion on anime names, and even for episodes I wrote auto completion give me last episode I watched + 1.
Anyone who is learning new stuff in this thread should really try fish, it makes using the command line so much nicer.
https://github.com/microsoft/inshellisense if you have to stay with Bash :)
Fish is such a nice shell.
I wrote a collection of small apps for fish a few weeks ago. If anyone wants to check it out: https://github.com/matdombrock/angler.fish
Finally, a command line shell for the 90s
😄
(originally debuted in the mid aughts)
I started out with bash, then eventually realized that I was using zsh because I’m a macbro. I’m a little slow :(
To be fair, they only switched to zsh in 2019, so a lot of tutorials probably still assume bash
for a while, i was so clueless that i didn’t even know i was using a zsh terminal. i thought i was in bash because i watched linux tutorials on youtube
Just tried it, working is indeed nicer after some nice fresh tuna and Sushi.
go with elvish, it’s new, sleek, and it even has functions that return functions, which means my plan to weaponize the english language by turning every word in a lower case punctuation free sentence into a series of shell commands is almost complete, MUAHAHAHAHA
EDIT: For legal reasons, this comment is just a shitpost, and I don’t know how to code. I’m just a lazy vibe coder.
-h
ls -Slut
These auto-completions are dependent on having the corresponding completions information installed and enabled. Which it is with most modern distros, but more bare-bones setups won’t have it.
I have two Linux VMs, one Fedora, the other Arch. I’m guessing tab autocompletes are built into those as well?
In case of Arch, for
bash, you have thebash-completionspackage, apart from which some program packages install their own bash completions.
Then there is alsozsh-completionsforzsh.I remember having to install them separately, but maybe you know some package group that did it for you.
Arch has the packages, but it won’t be installed by default.
oh yeah, arch is for nerds who wanna customize everything themselves. i’m new to arch so i forget sometimes
Incredibly stupid, but should work
My favorite kind of advice
For a moment I thought that ‘commandName -’ was some PowerShell stuff.
Powershell does that too
It can’t hurt to know this but to me PS is not intuitive, looks like SomeLongString-ActingLikeA-Command, and I avoid it as much as using Windows in the first place, unless absolutely necessary.
interesting, didn’t know that… Will try!
Finding out about “Ctrl-r” also was a gamechanger.
What does CTRL+R do?
Lets you easily and interactively search your command history.
Half the stuff I do is usually preceded by that, it’s really useful!Oh that is nice, I usually use ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
“I knew I had an ls somewhere in my history”
That’s part of the natural progression. Can’t remember if that comes before or after “history | grew command.”
Just wait until you discover fish/zsh autosuggestions.
As annoying as using a non-posix compatible shell sometimes is, fish saves me so much time
Adding fzf to the mix makes Ctrl+r even better.
Yeah standard bash Ctrl+r is just so painful. I much rather use “history | grep searchtearm” than that awfull search. fzf is a whole other level. But nowadays I just use fish shell which IMO has even better search than fzf
I have been suggested alternative programs to install to work with
Ctrl+r, which are supposed to work better, but I just end up usingkwrite ~/.bash_historywhenCtrl+rfails.
Next step is discovering atuin! https://atuin.sh/
Thanks!
Haven’t heard that one before. Comes on my growing list of all the stuff I wanna try/setup…I love atuin!
dude holy shit that is AWESOME! i had something similar, but it was a custom function.
srch() { cat ~/.bash_history | grep -Ein “$@”}
Did you know that grep can take the name of the file(s) you want it to search as the final arguments?
For example:
grep -Ein "$@" ~/.bash_historyi always pipe into grep so sometimes i forget that’s even an option, lol
I accidentally stumbled across Ctrl+r over a decade ago and I still don’t understand properly how it works. So I usually egrep -e someInsaneRegex ~/.bash_history
The part of the tech stack that handles all these command editing and navigation shortcuts is the readline library. Check out
man readline. There’s an entire section on searching. readline is used for lots of other interpreters, too.That is worth it for more complicated things like, “I want all commands that started with git and contained ‘foo’”
Did it like that before, but Ctrl-r is typically just a lot faster.
Ctrl+r is cool, but atuin is oh my gosh great
isn’t that just fzf with ctrl-R binding
I used fzf before atuin, and it works pretty similar, but atuin has a few additional features, as it tracks more information than the normal shell history. For example, you can also search only for commands that you executed in the current directory (great for stuff that is project specific). Or, if you use the history syncing feature, you can toggle search for commands you executed on either any or only the current machine.
I didn’t know fzf yet. Neat
Y’all need to install Arch, you learn all the basics pretty much instantly… That or drown when you can’t install the boot loader.
Btw
Does it depend on some shell or shell extension? My bare bones Debian installs don’t do this. Powershell does but I’d like it on Linux too.
powershell? eww
Powershell is apparently pretty well designed. I’ve not used it myself.
one of my instructors called it “the land of the dead”
Well it does have “hell” in it’s name
I think on Debian you need to install bash-completion to get bash to complete flags.
Thanks I’ll try that
You can install powershell on Linux if you’re feeling masochistic
I take PowerShell ForEach-Object any day over the unholy contraptions of awk, xargs and friends in bash.
for $variable in $(collection command); do
other-command $variable;
doneHm TIL, fair enough. Thanks.
But chaining still seems harder than
CommandA | ForEach-Object { DoSomethingWith $_ } | CommandBIf you feel like learning a third shell, I find that Nushell is even easier to use than PowerShell.
open stuff.json | each { get fieldName } | where { str starts-with "asdf" } | each { $in | str upcase }This gets all the objects in the given json file, then grabs the value of the field named “fieldName”, then filters all those values to find the ones that start with and, converts those to uppercase, and prints them to the screen as a nicely formatted list
You don’t need the
$in |in that last command.each { str upcase }will already pipe each item to thestr upcasecommand.
Yeah, it does tend to be hard to determine when to use
(){}[]etc.
Even after I RTFM and used those in scripts multiple times, I tend to forget it by the time I need to implement something next.
yeah you’ll have to install some helper scripts or switch to either fish or zsh. bash is nicer than bourne shell, but it is VERY basic in features by modern standards
zsh does this with oh-my-zsh, as well as many other “extra” completions
ZSH still needs the completion data files to be installed. It won’t just magically know the completions.
Ah you’re right, my bad. I automatically install oh-my-zsh so I forget how much functionality is bundled into it. Edited
I don’t know the answer but does tab to autocomplete work in other contexts? E.g. you type ‘cd ca’ and it fills it to ‘cd catpics’?
I’m not at a PC right now but from memory you’d have to be in bash or similar, it won’t work in sh.
Yeah tab completion works for file paths but not command arguments
Why not just install tealdeer tho??
implying i know what the fuck a teal deer is
A TLDR alternative to man pages
While a man page is for every possible flag available for a command,
A tldr is for the most common tasks a command can do.tldr fcfc Open the most recent command for editing and then run it. More information: https://www.gnu.org/software/bash/manual/bash.html#index-fc. - Open the last command in the default system editor and run it after editing: fc - Specify an editor to open with: fc -e 'emacs' - List recent commands from history: fc -l - List recent commands in reverse order: fc -l -r - Edit and run a command from history: fc number - Edit commands in a given interval and run them: fc '416' '420' - Display help: fc --help
It really depends on þe shell, þe d distribution’s default configuration, and þe commands. Shells will often load a config from
/etc/profile.dor someplace like þat; if þe distro doesn’t enable features like autocomplete or history, and you haven’t enabled it in$HOME, you won’t get it. Also, commands need to provide autocomplete hints for the shell; it’s not automatic.Ég þekki ekki efri stigin í spákonunni minni. Ég held mig bara við heimaskrána. Pabbi minn segir mér að efri stigin séu land hinna ódauðu.
