@Bryan2333, thanks for this. Really cool.

1. is there a way to statically check this (and/or format) as we do with shellcheck and shfmt for e.g. Bash?

2. does it cover all commands? Or is something missing?

1. There is no linter for fish shell script so far. If we need to check the syntax of the script, I think the only way is to run the script directly.
2. Yes, it cover all commands of kerl.

Yeah, I installed fish ran fish -n on the file and there were no errors. Could you update the README with instructions similar to bash/zsh's (I'll post the md below, for copy-paste ease). Thanks.

### Command-line completion

Optionally, download and install `kerl`'s:

- `bash_completion` file from <https://github.com/kerl/kerl/raw/master/bash_completion/kerl>
- `zsh_completion` file from <https://github.com/kerl/kerl/raw/master/zsh_completion/_kerl>
- `fish-completion` file from <https://github.com/kerl/kerl/raw/master/fish_completion/kerl.fish>

depending on your preferred shell.

Merging... thanks much for this. If you need a release soonish feel free to let us know.