With fish, if the program you're interested in hasn't betrayed the decades-old tradition of shipping man pages, it's often as simple as running `fish_update_completions`.
It parses all man pages on your system and generates completion files for you. By default, they go into ~/.cache/fish/generated_completions/*
If the man page was written poorly/is missing, you can always write your own completion (and hopefully send it upstream). fish uses such a simple format that I don't think there's any need for tutorials save the official doc:
https://fishshell.com/docs/current/completions.html
For example, here's an excerpt from curl
complete --command curl --short-option 'L' --long-option 'location' --description 'Follow redirects'
complete --command curl --short-option 'O' --long-option 'remote-name' --description 'Write output to file named as remote file'
When I screen share, people don't realize I'm not using zsh and dozen plugins. It's just fish and it's beautiful out of the box.
I'll switch to fish after it stops expanding `car TAB` to `blkdiscard` when I don't have `cargo` in path. Non-prefix completion for commands is plain evil.
I’ll switch to fish when it comes preinstalled on all of the computers I use so I can write scripts in it.
I already avoid bash scripting so I lose very little. Shell scripting beyond throwaway one-liners is a problem not a solution.
(Well that and all my machines come from the same NixOS configs.)
Ha that’s funny, considering nixos is 99% stdenv which is one of the worst bash monstrosities in existence, and drives people ever further into the swamp of bash. (Ever tried to debug stdenv setup hooks? I still have water damage from the tears.)
I have personally embraced the insanity but let’s not kid ourselves about nixos basically just being three bashes in a trench coat.
Basically https://xkcd.com/224/ , but s/lisp/nix/ s/perl/bash/
It's my daily driver, but I am holding my nose.
Some year something better will show up from someone with more taste (and I know I am not alone in having thoughts on what it would look like), but for now the yak has already been shaven. At least the builds are sandboxed.
Guix if you can stomach it.
Do you really limit your shell experience to plain POSIX? That sounds masochistic.
Ever since shellcheck came around I have been writing all my scripts in POSIX sh. Its not that bad actually and knowing stuff is just more compatible is worth that little friction.
Shellcheck has been a huge game changer for me. The lack of a linter is the main reason I don't consider switching to zsh anymore.
When I first found shellcheck, I'd sit on the train every morning and fix all the stupid little bugs in all our shell code. I learned a TON about shell scripting, because the shellcheck wiki is amazing. We had some redhat 6 init scripts checked into our repos, and shellcheck helpd me find syntax errors in those init scripts. If Redhat can't reliably write shell scripts without a linter, or catch bugs from upstream, what makes us think we're any better?
I wouldn't write serious programs in another language without a linter. Why should I write shell scripts without one?
You shouldn't be writing serious programs in Bash/Zsh at all, is the issue. If it's complex enough to need linting, it's complex enough to require Python/Perl.
Writing all your scripts that way is one thing. I’m not that far off, although I write all my shell functions and things like that in fish. But avoiding using tools that may not be universally available means never using ripgrep or fd or fish or newer versions of bash or any of the other nice updates we have now, and that sounds awful.
I would rather limit myself to things I know are going to be preinstalled on the platforms I use than deal with the masochism that is scripted dependency management. No thanks.
All these comments here "Uhhh just use PythoN!" Yeah? I write scripts that need to run on macOS. No Python there. Yeah I can have my script sit there and pull the command line tools in an automated way and wait the 20 minutes it takes to install or I can pull on my big boy pants and just figure out how to do it in shell. It's turing complete. It works. Whatever.
MacOS doesn’t have python? What?
macOS has not shipped with Python installed in 6 years. If you take a Mac out of the box, open terminal, and run `python` it prompts you in the GUI to install the Command Line Developer Tools.
Thanks GPLv3
That's why I use C to write all my shell scripts. Can't have something non-portable like bash, which is missing from 75% of computers by default.
(Seriously, what am I missing here? Is `apt-brew pacman install fish` really that hard to type? If cross-platform portability is actually a concern, shouldn't you be using Python anyway?)
I don't really care about portability as I do "how much shit do I need to install to actually get work done on my workstations and servers"
Maybe it's because I was a sysadmin in a former life, but overmanaging is almost always a mistake. If I had one single computer and only one, sure, who cares. But I have a homelab full of servers and a constant churn of VMs and I don't need to add in another step of "oh shit X isn't installed yet". Maybe it's also because of that that I don't really give a shit about how "bad" sh/bash/zsh are.
Yes, I can sync dotfiles and crap to git (which I also have to install to use), but it's just a small weight off my shoulders to not have to worry or think about that shit before I can use a server or workstation. I don't want to have to unlearn normal shell to learn fish and then have to switch back when I'm trying to get some thing online so that I can install fish. I'm just not fuckin interested.
(inb4 someone is like nix solves this, i don't give a shit about nix either)
I bet this is configurable but I wanted to say that this is totally personal preference; I have the exact opposite opinion. Prefix only matching requires much more tab slapping in my experience.
I believe you would lose that bet. I look every few years and I don't see it
interestingly this also seems to have come up pretty recently in their discussions.
https://github.com/fish-shell/fish-shell/discussions/11670#d...
> I'm not sure that subsequence matching ever produces results that people expect (I feel like we've discussed this before but haven't had time to go digging)
No solution, but the discussion seems positive, from a maintainer too.
I gave up on fish after a few weeks because of a similar preference issue where the fish maintainers flat out refused to make a bad default configurable: https://github.com/fish-shell/fish-shell/issues/8618
> We don't really do config flags like this, as a philosophical point.
> I would be against accepting such a PR. I do not believe this should be changed.
I understand that they want to keep the list of configs short and manageable, but it means that's not a tool for me. I'm all for good, opinionated defaults but I want to be able to make some changes if I want to.
They apparently reconsidered and implemented the change since migrating fish to rust though.
For those programs that have betrayed shipping man pages, instead say relying only on a --help system, do you happen to know if the fish shell has an analogue to Zsh `_gnu_generic` and Bash `complete -F _longopt`? If not, do you have any insight into why not/what it would take to make that happen?
At least for a subset of Python CLI programs, I wrote this: https://github.com/AdrianVollmer/pycompgen
Still in an early stage, but it should work.
The OP mentions them in the last part of their comment, there is `complete …` commands for registering completions
It sounds like you don't know how the Bash/Zsh ideas I mentioned work. They run the command with --help, parse the output, and from that generate the completions, wiring them in to the completion system. That method is a zero config solution (well, you might need a list of such "command-names only" - no option names, which could change at any time -- so maybe "minimal config"). The OP & you mention a much heavier config solution which strikes me as against the vibe of Fish in general which is, supposedly, out-of-the-box niceness.
Thank you for the comment. https://github.com/umlx5h/zsh-manpage-completion-generator appears to adapt this to ZSH. Have yet to try through
It's surprising that on OpenSUSE `zypper search fish-completion` returns more than 200 packages. Something is fishy here.
That is to get live data in your completions.
Say you have a widget that has 3 commands: list, start and stop.
With one of those completion files widget stop <tab> will show you a tab-able list of widgets which are running.
man pages are so underrated. I mean every project nowadays has README.md so I don’t see why we can’t just auto generate them with or without an LLM helping. Also I wish programs would use standardized generic arguments for help, config file, version, background the task, PID file, log file, and log level.
oh wow, it's parsing all 9461 man pages on my arch install, for a cute total of 13MB
thanks a lot
Fish isn’t the only shell that does this. Murex has supported man page completions for years too. And it’s fully automatic in Murex.
I tried to use fish on some of my debian servers that i only rarely update packages/kernel, so I don't have to carry my bashrc there, but found their completion for apt is pretty naive. for example after updated kernel i would want to clean up the old ones, but `apt purge linux-image-<TAB>` would list all available kernel versions, not just the ones currently installed.
in the end i switched back to bash.