Cli: getopt flag syntax?

[boyvinall]

Thanks for the awesome library, I've been using it for years.

Just wondering if you're interested in supporting standard GNU getopt() syntax? This is the one thing I feel this project could benefit from. At the moment it's just an idea, though I'd be happy to do the work and send a PR if you agree. A quick google for "golang getopt" shows a number of existing implementations, so it should just be a matter of picking one of those and hooking it in appropriately?

FYI, the end-user impact of this would be as follows. Say you have the following flag definitions:

cli.IntFlag{
    Name:  "n",
    Usage: "max number of things",
},
cli.BoolFlag{
    Name:  "quiet, q",
    Usage: "Reduces the text output",
},
cli.BoolFlag{
    Name:  "all, a",
    Usage: "show deleted stuff too",
},

then currently the CLI user has to type:

-a -q -n 1

but getopt() allows you to type:

-aqn1

[boyvinall]

Hey Dan @meatballhat, I opened this issue really just to get some initial feedback. As I said, I'd be happy to submit a PR if you like the idea.

[lynncyrin]

Hi @boyvinall I'd be happy to review a PR for this, if you're still interested!

[boyvinall]

Hi @lynncyrin, will see if I get some time but things are fairly busy. I've thought about this a bit more since opening it though .. I realised that the long flag name form is currently accepted with either a single or double dash (--flag or -flag) which would conflict with this. So if this issue is resolved then I guess, for backwards compatibility, it would need to be conditionally enabled. Your thoughts on that?

[AudriusButkevicius]

Isn't this solved on master? You have to single dash for short opt expansion (which is standard) in this library I believe.

[lynncyrin]

So if this issue is resolved then I guess, for backwards compatibility, it would need to be conditionally enabled. Your thoughts on that?

I believe this is what the UseShortOptionHandling option does? Please correct me if that's wrong!

[lynncyrin]

This has been sitting idle for a while, so I'll circle back and close it soon - unless someone wants to keep it open!

[boyvinall]

Sorry for going quiet. Yeah, I hadn't noticed UseShortOptionHandling, that looks like the thing, thanks.