Isn't there a standard flag which programs can implement to avoid writing this bash script?
Ideally this could all be part of a library such as argparse for typical cases, right?
Isn't there a standard flag which programs can implement to avoid writing this bash script?
Ideally this could all be part of a library such as argparse for typical cases, right?
In zsh you can use the _gnu_generic function for simple completion of commands with a --help flag. Just put a line like this somewhere in your startup file: compdef _gnu_generic <CMD>
_gnu_generic is fantastic. I use it all the time. If your CLI toolkit emits colorized help, but skips said colorization if NO_COLOR[1] is set then you can prefix _gnu_generic with NO_COLOR=1 as in https://github.com/c-blake/cligen/wiki/Zsh-completion-for-cl... for the cligen Nim CLI toolkit.
A similar thing in Bash is `complete -F _longopt YourCmd`, but these will not work with "multi-commands" that have "sub-commands" as the article of this thread covers. Truth is, as non-standard as GNU long opts already are, how subcommands work is even more non-standard (are there even global options? Or between each subcommand? Is it how Python does it? Or Go? Or some one specific library or ..?)
[^1]: https://no-color.org/
Rust has the clap_complete package for its most popular arg parsing library: https://crates.io/crates/clap_complete
ripgrep exposes its (bespoke) shell completion and man page generation through a --generate option: rg --generate=man, rg --generate=complete-bash, etcetera. In xh (clap-based) we provide the same but AFAIK we're the only one to copy that interface.
Symfony (for PHP) provides some kind of runtime completion generation but I don't know the details.
I've wondered this as well - it would sure be nice if there was a standard --completion or something that common argument parsing libraries could automatically implement for us (much like they often implement automatic help text)