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Comment by jayvanguard | Hacker News Reader

Good idea. I wonder if anyone has done this for general unix command-line apps by parsing out the man pages on the fly. It probably wouldn't work for all programs but may be gnu style ones would be consistent enough.

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I too was expecting something like what you describe but by parsing -h --help output.

The bash-completion script can deduce which options are supported by an application by parsing the output of --help and of usage lines. In Bash.

http://anonscm.debian.org/cgit/bash-completion/bash-completi...

Either way, it might be neat to do it dynamically, so command-line programs could be turned into guis live by typing "guify xyz".

The gui could have labels with the command options, and upon hitting enter they could close and send the command back to the command line, so you're learning the commands as you go.

The Python "argcomplete" module[1] generates shell completions for any program that uses argparse, so it's certainly doable.

[1] https://github.com/kislyuk/argcomplete

> parsing out the man pages

https://github.com/idank/explainshell

I've done something similar to this a few times, both in Python.

Once to create a TkInter GUI for an internal command line app, and once to wrap sg3_utils for use in Python scripts.

In general, I think it could "mostly work" a good portion of the time, but it'd be pretty difficult to get working 100% of the time without a lot of tweaking to the parser.

The fish shell does this with an explicit command (fish_update_completions) and offers an awesome Tab completion in the current Github version

Not far from that there's docopt who parses POSIX compliant arguments descriptions.

Is there such a thing as POSIX-compliant argument descriptions? I know POSIX specifies some things about the format of options, but I didn't realize there was a formalized option description language.

Yes. IEEE Std. 1003.1 Utility Conventions

http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_...

This is actually how Docopt happened (Vladimir Keleshev mentioned it in the PyCon UK 2012 talk).

Cool! Thanks for the reference :)

Me neither, I thought docopt was a hardcoded fragile thing, until the author explains everything is almost perfectly defined.

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