Support zsh

[eigengrau]

So, I’ve noticed quite a while ago that zsh support had been removed. So, since christmas is a time for miracles, I thought I might check back on any recent developments. From searching the issue tracker I take it that nothing has changed in this regard. So I figured I might open this issue so that patient, interested parties can subscribe to it and get notified in case someone feels like stepping up.

That is of course if you do deem zsh support generally useful. Otherwise please feel free to close the issue.

Thanks for making shellcheck!

[HaleTom]

shellcheck is amazing, and it is the reason I still write most of my scripts in bash.

I'd love it if zsh support could be added though!

[molovo]

As someone with quite a few big ZSH projects out in the wild, I'd definitely be interested in seeing this happen. I'd be very happy to contribute myself if someone could let me know what would be required to get it implemented.

[bittorf]

@molovo: first you have to ask yourself if the features of 'zsh' are a subset of other shells or if zsh has own features. look into the source for 'first citizen shells' and the handling of 'dash' and 'bash' and you will get a feeling, what is needed...

[koalaman]

This would require:

1. Implementing all the syntax that is unique to zsh, to allow scripts to be successfully parsed (Parser.hs). This requires some care to avoid strange parse errors for other shells.
2. Extend the variable flow tracing code and similar to support these new structures, so that shellcheck can tell when variables are modified and such (AnalyzerLib.hs).
3. Fixing or extending any tests that are not correct for zsh (Analytics.hs, Checks/*.hs).
4. Adding new and interesting Zsh specific checks.

Ksh shares basically all its syntax with Bash, which is why it's still supported even though almost no one uses it. Zsh required a lot more work for a similarly small number of users, which is why I unfortunately wasn't able to keep it up.

[LukeShu]

If zsh is ever supported, it should recognize #compdef and #autoload as shebangs for zsh, as these are magic headers used in zsh autocompletion helpers.

[kgizdov]

@koalaman I understand that bash is way more popular that zsh, but it still has a huge community. Would it be appropriate if you make a project/branch for zsh contributions so that users can contribute. Maybe put a note in the README and helpwanted flag here. If you set up the infrastructure, I'm sure people will bunch up to make this happen. I am willing to spare some time on this.

[brother]

@kgizdov on the other hand a PR with the start is pretty much the same. I assume that if you gather some people to do the work either they are welcome to the project or they will fork it.
The code won't be written and maintain by pure magic, as far as I can understand @koalaman will not take that responsibility himself.

[paulmelnikow]

I looked into this briefly a couple weeks ago. After I read through most of Parser.hs it was apparent that koalaman's step 1 would require deep knowledge of zsh syntax and bash syntax and a decent understanding of Haskell.

That made me wonder if zsh's parser (it's in C) could be used directly or modified slightly to emit an AST that could be interfaced to some high-level language constructs in Haskell or some other language. The wrapping is a bit involved, but is less work than reimplementing the parser.

I'm curious, has anyone on this thread worked with the zsh source?

[molovo]

@paulmelnikow I haven't worked with the source, but I have considered building an AST or something similiar (not for this purpose, but to support a coverage driver for zunit). I wonder if something could be built to tackle both issues at once?

[paulmelnikow]

@molovo Interesting idea!

[snoblenet]

Maybe the wiki could recommend a shellcheck alternative for zsh users? Because all Google searches based on variants of lint zsh take you back to shellcheck.

[paulmelnikow]

Unfortunately, there is no such equivalent. If anyone could make it happen, that'd be @molovo.

You may want to take a look at fish shell, which is better documented, more user-friendly, and developed on github.

I would like a support for Zsh but well Bash is still pre-installed in all major distro.

I code in Bash using Zsh...haha