Fish: A command line shell for the 90s

by kick • 7 years ago

149 83 7 years ago

llarsson• 7 years ago

I love the way it predicts what I will write, how attractively it presents the predictions, and how it understands commands and completions based on man pages.

But with decades of bash experience, I struggle with making even the slightest scripting in fish's own language for whenever I want to make a smart little addition to my environment.

snide• 7 years ago

So somewhat unique experience. I'm a designer. I code. React and css mostly. I do use Vim which I guess is weird for a designer.

I love Fish. I'm likely not their target audience.

I've been using it for years. Since the early days in 1.x land for sure. The homepage has never changed and I still laugh at the tagline. I find it's auto-completion, history and niceties indispensable. I'm the person who asks you what the command is to rerun the tests. With Fish I never have to ask you again. I just remember part of it, and suddenly I've got it.

I find its scripting language much simpler to follow than bash. I don't have a lot of scripts, but the ones I do are easy to manage. The only hiccup I get into is when I have to look up something on stack exchange, and of course the example is in Bash. These days though, with Bass and fisherman and so many other tools, i have options.

Years ago I would explain to other code friendly designers, I'm weird, don't use this stuff. Go grab zsh. Lately though it's gotten very friendly. Really the only downside for a light scripter like myself is that need to convert bash examples to fish problem. Beyond that I feel it's actually a much nicer shell for new to terminal folks.

Anyways, just an anecdote to add to the pile. Thank you to the devs that have supported it over the years.

Aloha• 7 years ago

fish is my preferred interactive shell (I have window 0 on screen set to be fish), I still write all the scripting I do in bash, because I know it's probably already installed out of the box.

Until you raised this point I didn't think if fish as something you'd script with.

L0stLink• 7 years ago

I really love the syntax and performance of fish shell, I had a few bash scripts that were used to manage the system volume notifications and power/battery information, as I use fish as my interactive shell, I ported them over to fish and tried to compare the performance, and to my surprise the fish variant was faster. I decided to rewrite the random wallpaper script for sway in fish too and it runs much faster then the original python snippet I got from swaywm's issues[0] (link to original python script[1]):

    #!/usr/bin/env fish
    swaymsg 'output "*" background ~/Pictures/Wallpaper/'(ls ~/Pictures/Wallpaper | shuf -n 1)' fill'

I really love fish shell and find its multi-line input extremely valuable, I think it has a much saner syntax (I have no meaningful experience writing bash scripts), if you are like me in this regard I highly recommend writing your personal scripts in fish instead and if you are worried about posix compliance, it is not that different from a bash script with bashisms in that regard.

[0] https://github.com/swaywm/sway/issues/1269#issuecomment-4316... [1] https://git.sr.ht/%7Esircmpwn/dotfiles/tree/master/bin/wallp...

manaskarekar• 7 years ago

With Fish I never have to ask you again. I just remember part of it, and suddenly I've got it.

Are you referring to something other than cycling through history?

In bash, hit `Ctrl+R`, then type whatever part of the command to cycle through history.

You may choose to adjust the size of the history file in `.bashrc` as needed.

A good reference: https://www.digitalocean.com/community/tutorials/how-to-use-...

toxik• 7 years ago

Fish autocompletes history

AnthonBerg4• 7 years ago

The Fish interface for this is much more convenient and elegant and ergonomic.

lain• 7 years ago

With bash, I like to put this in my `.inputrc`, so I can start typing a command, and use the up and down arrow keys to autocomplete:

  "\e[A": history-search-backward
  "\e[B": history-search-forward

tmysl• 7 years ago

As nice as fish is, it's not fully posix compliant, leads to some weird bugs here and there

akx• 7 years ago

Those are probably bugs you could report to the project.

kick• 7 years ago

They're intentional.

They have considered a compatibility layer in the past:

https://github.com/fish-shell/fish-shell/wiki/POSIX-compatib...

pmarin2• 7 years ago

For interactive shells do not matter if is not POSIX compliant. I use csh (the really old one) as interactive shell.

e12e4• 7 years ago

Yes and no. One nice thing about shell, is that you can log your commands/look at your history - and easily automate tasks (turn an interactive session into a script).

The only trouble is, such snippets have a way of sneaking into documentation, ci pipelines and other places.

And then non-posix isn't quite as nice anymore. Even if csh or fish might be the nicer language.

I do think the oil shell project is on the right track, by trying to "fix" shell (and fish is a great source of inspiration for the interactive part).

Still, when plan9 didn't manage to take over, I guess I'm a bit sceptical about any new shell having much success...

kbumsik• 7 years ago

It matters a lot when dealing with default environment variables. Even when expanding $PATH fish will give you much headache.

pushpop• 7 years ago

Is it really a “bug” if you’re writing incompatible code for Fish? Bug implies unexpected behaviour but I’d argue that Fish’s non-POSIX behaviour is well discussed, documented, and thus should be completely expected.

rgoulter• 7 years ago

AFAIR the problems using fish tend to be when other programs (e.g. vim or whatever) try and interact with the shell and it's non-POSIX compliant.

The "expect it to work, didn't" is more on the user's side, going from e.g. bash to fish.

Symmetry• 7 years ago

I recommend leaving bash as your system shell and just telling your terminal emulators to start with fish.

aiyodev• 7 years ago

If you install fish, you should also install ohmyfish so you can install a good theme. I like bobthefish:

https://github.com/oh-my-fish/oh-my-fish/blob/master/docs/Th...

mxschumacher• 7 years ago

or sushi, I've been using that one for a few years:

https://github.com/umayr/theme-sushi

e12e4• 7 years ago

To each their own - I'm so glad fish doesn't come with something like this out of the box! :)

blondin• 7 years ago

love fish. but love compatibility with bash most.

phonebucket• 7 years ago

Love this shell. Sensible defaults make it so quick to get up and running too.

atemerev3• 7 years ago

Yes, the only shell I actually enjoy writing scripts with. Bash is old and ad-hoc, and zsh is basically bash on steroids. Fish is something where actual language designers have sit and thought thoroughly how the shell language should work and look like.

chrysoprace2• 7 years ago

Fish is great, and it brought about some great defaults such as autocompletion and autosuggestion. The only drawback is the incompatibility with bash.

The wonderful community made plugins that add these features to zsh (which IS compatible with bash), and it it's really great. My understanding is that there are still a couple fish features not implemented for zsh yet, but if you care about such things as bash compatibility then I'd suggest you give it a try instead.

VvR-Ox• 7 years ago

I agree. The auto-features should be default for bash as well as it would really help some novices to get more fun out of the experience learning to use a shell and also as an experienced user I wouldn't want to miss this.

Because of that on every computer I have to work with for some time one of the first things is installing ZSH (and prezto).

yoloClin5• 7 years ago

My understanding is that there are still a couple fish features not implemented for zsh yet

I'd love to know which ones! I was a bash user for 10 years, ZSH defaults put me off and it wasn't till I ran oh-my-zsh that I really learnt what I was missing, the following make me feel like a 10x-er ;) :

- zsh-autosuggetions - zsh-syntax-highlighting - colored-man-pages

Edit: And the `zstyle ':completion:*' menu select` autocomplete

chrysoprace2• 7 years ago

I've not used fish extensively so I couldn't tell you. My statement is mostly based on impressions from other people who have also tried both. I should give fish another go and see how I like it, but the bash incompatibility is a deal-breaker for it to become my daily driver.

einpoklum2• 7 years ago

Can someone give a few prominent examples of fundamental differences from bash? I don't mean trivial things like having `config.fish` instead of `.bashrc`, or not using fi and esac to conclude if and case statements.

I noticed fish has:

* extensive syntax highlighting

* "global" variables shared by all instances of fish, persisting past reboots.

what are other important features?

atemerev3• 7 years ago

Good and well-thought shell language syntax (compared to ad-hoc hodgepodge of syntactic peculiarities of bash/zsh); reasonable defaults for the interactive shell. No other shell gives you this, for some reason.

hnlmorg4• 7 years ago

No other shell gives you this, for some reason.

That's not true. There are a few other shells out there that do. The issue is the popular shells tend to be the ones that go for POSIX (or Bash) compatibility and those that do go for a syntax redesign (for example) often get criticised for not being POSIX compatible. There is comment further down in this discussion describing those syntax differences as "bugs" rather than "features"; which just goes to demonstrate how ingrained Bash et al are to Linux/UNIX command line users.

Personally I see Fish and other non-POSIX shells like another programming language (arguably that's literally what they are). So switching from Bash to Fish - or whatever else - should be like switching from C++ to C#, Java, Rust, whatever. Sure there will be a lot of commonalities but it is the differences what makes the shift worthwhile.

That all said, I can't blame people for preferring a POSIX or Bash compatible shell because that's what you'd expect to find on any Linux or UNIX system. Or at the very least a Bourne Shell (sh). Plus most documentation online will be tailored for compliant shells. However it does become a self-fulling prophecy where compliant shells are more widely used because they're already more widely used. I'm fine with this though. People who want to make the shift and learn something new can still do so under the knowledge that they're breaking from the norms and all the potential complications that might bring; and people who just want something that's universal and works - irrespective of it's warts - can continue to do so.

einpoklum2• 7 years ago

Can you give a couple of examples (and I mean - things I might actually type in an interactive shell)?

Quequau• 7 years ago

For me the killer feature is that for me, as a casual user, it's easier to be productive. There are just so many weird little things that folks do in shells that I don't do often enough for me to remember exactly how to do them.

Though I'll say up front, again as a casual user, I'm not sure exactly how fish accomplishes making me more productive than bash. I'm also don't know if I ought to switch to something like zsh. I often read folks saying great things about zsh but it seems more like something aimed at "power users" and that ain't me.

yoloClin5• 7 years ago

oh-my-zsh has 'sane' defaults (and by that I mean 4-8 hours of configuration at least). I'm in the process of moving from that to self-managed zsh and I'm surprised with the stuff that doesn't come default with ZSH, such as not setting the <title> of the shell to $(pwd) or the currently executing process, or control codes.

maverwa• 7 years ago

Comes out of the box with a lot of useful auto completes, highlighting etc. Can do most of this with zsh and a lot of scripts/config but in fish it „just works“. Except you have to learn a new language. () for $(), „; and“ instead of „&&“ etc.

saila• 7 years ago

&& and || are supported in the latest version of fish (I think starting with 3.0).

e12e4• 7 years ago

Many great responses here.

I've considered switching from bash to fish (something I never did with zsh). The main reason I didn't is Stockholm syndrome, or that I'm too used to bash by now.

I think you can get zsh to do most of what fish does out of the box. If bash is Ed, it feels zsh is emacs and fish is (neo)vim.

Zsh is huge and I always get a bit of a panic attack when someone has given me a ssh login with zsh as the default shell. And an irrational urge to maul a unicorn.

With fish, it feels more like a friend went and tidied up your apartment just to be nice.

I guess I'm so used to bash, that the limited support that comes from completions is enough - and I end up writing a bit of documentation and automation, and work on "foreign" (other people's) servers - and it helps me to work in a posix shell for that reason - with fewer surprises.

You might even find that fish does out of the box something bash (now) can too - just isn't enabled by default or in typical distribution's configs.

Ymmv - it's worth testing imnho. And more interesting than zsh, which just feels like someone was bored in it class in high school and added colors and tinkered with the prompt, and tried à million different ideas - but never really liked working in shell.

AnthonBerg4• 7 years ago

Maybe I did it wrong, but I tried zsh and used some common packages and things to get it to work like Fish. zsh became super slow.

yjftsjthsd-h2• 7 years ago

If bash is Ed, it feels zsh is emacs and fish is (neo)vim.

I would have thought fish=emacs and zsh=vim in this analogy, since fish isn't really compatible with bash but zsh is?

ufo• 7 years ago

A big one is that unquoted variable expansion does not split on whitespace. This avoids all sorts of spaces-in-filenames bugs.

For a similar reason, command substitution only splits on newlines. Unfortunately, some commands like pkg-config assume that the shell splits on regular spaces so you will need to use workarounds like (pkg-config | string split "")

airesQ• 7 years ago

I feel like there is a big audience for fish with bash support.

This could be a nice project; lets call it "shark".

CJefferson• 7 years ago

I want to love fish, but I get annoyed by the lack of true subshells. I love being able to write things like:

(cd dir; make) &

To start some stuff in the background, but with fish directory and variable changes in () don't stay inside the ().

cormacrelf3• 7 years ago

This comes up every time Fish makes it to HN. It still bugs me too. So does up-arrow skipping the first matching history item and having to use right-arrow for the ghost entry that shows up. These two are 100% enough for me to change shells, and I will. Fingers crossed NuShell does well!

losvedir• 7 years ago

What's the problem with right arrow? I use ctrl+e (a la emacs) to accept the ghost completion.

lijogdfljk• 7 years ago

Can you describe what you like about NuShell? Never heard of it, but the Github page looks super interesting.

I struggle to imagine making use of it however. My normal flow just doesn't seem to need that power. I think I would benefit most from simplicity. Although, I could definitely see this benefiting from things being predictable, guessable, etc. Ie, when I rarely need more advanced features I'm less likely to need to look up documentation to figure out how to do something - as I often do.

meddlepal• 7 years ago

This is why I gave up on fish and went to zsh. It was always a headache.

ylere• 7 years ago

I've been using fish as my default shell for a long time and recently started using it with https://starship.rs/, which adds some niceties to the prompt without having to go overboard with customizing and configuring your shell.

VLM• 7 years ago

Something not discussed enough is the competing concepts of shell as hyper customizable UI where fish wins, and shell as a light programming language for short casual scripting, where I kinda have to use standard uncustomized bog standard identical everywhere bash.

resonious• 7 years ago

This might make me a bit of a freak, but the one thing keeping me from trying out Fish for real is decent vim bindings. I know Fish has vim bindings, but I found the feature support pretty lackluster and the behavior of some keys like 'e' to be inaccurate.

I know some folks say that vim-style editing is overkill for a shell where you're often just submitting one-liners, but it saves so much time for me to be able to just jump right into the middle of a previous command and change one word without holding down arrow keys to get there.

Granted, it's been awhile since I looked into Fish's vim mode, so maybe it's improved. Last time I checked, it sounded like it just wasn't a priority, since Fish's selling point is the intelligent autocomplete and such.

raimue• 7 years ago

If you are working on a complex, long command pipeline, in bash you can use Ctrl-x Ctrl-e to open your $EDITOR to edit the line as needed. The commands will be executed as soon as you save the file and exit.

achikin• 7 years ago

Alt(Option)-e in fish does the same.

armSixtyFour• 7 years ago

I use vim binding in the shell a lot, typically for stringing a bunch of commands together. For replacing one word would using the `^` work?

ex: `$ echo "hello"` > hello `$ ^hello^goodbye` > echo "goodbye" > goodbye

nmstoker• 7 years ago

Purely superficial comment:

Thought they were being ironic with the 90s / Netscape / glorious VGA comments but maybe these really haven't been updated in an age. They've got screenshots not updated since 2006 (based on the release date in GitHub for release 1.21, given version 1.21 is show in one of the screenshots! You can also tell they're older from the chrome on the Mac terminal title bars)

otakucode• 7 years ago

I think they're just being honest. All of the features they boast were completely possible in the 90s. The only reason we didn't get them in the 90s was people not realizing they were so possible, or perhaps not wanting to leave their 70s style behind. A great deal of computing, especially on the *nixy side of things, is stuck in the past. Stepping back and looking at what you're used to and saying 'but how would it work if we were designing it from scratch today with all the hardware and knowledge we have now' doesn't often come up. And it's often seen as an attack on the older way of doing things for no good reason.

WalterGR• 7 years ago

Fish was first released in 2005. They're being cheeky.

It looks like the project didn't start calling itself a shell for the 90s until 2013. At least on the project's home page. Compare

* https://web.archive.org/web/20130420050628/http://fishshell....

* https://web.archive.org/web/20130521005841/http://fishshell....

YuukiRey• 7 years ago

I use it as my daily driver and I've also started writing some smallish scripts in it. It's actually fun whereas bash always seemed rather tedious. I love how easy it is to parse arguments with `argparse` and to add completions through `complete`.

Also fish utils like `string join` etc. are super helpful when writing small scripts.

Shameless plug: https://github.com/cideM/fish-yvm yarn version manager written in fish

Fish: A command line shell for the 90s

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