What's the difference between argp and getopt?

Question

I think the title is self explanatory. I am making a program and I was wondering what I should use of the two and why.

Answer 1

argp may be more flexible / powerful / etc, but getopt is part of the POSIX standard. Thats a choice you've to make based on whether you expect your program to be portable.

Answer 2

From the Argp manual:

Argp provides features unavailable in the more commonly used getopt interface. These features include automatically producing output in response to the ‘--help’ and ‘--version’ options, as described in the GNU coding standards. Using argp makes it less likely that programmers will neglect to implement these additional options or keep them up to date.

Answer 3

There's not much to choose I don't think. The Argp webpage says this:

Argp provides features unavailable in the more commonly used getopt interface. These features include automatically producing output in response to the ‘--help’ and ‘--version’ options, as described in the GNU coding standards. Using argp makes it less likely that programmers will neglect to implement these additional options or keep them up to date.

Argp also provides the ability to merge several independently defined option parsers into one, mediating conflicts between them and making the result appear seamless. A library can export an argp option parser that user programs might employ in conjunction with their own option parsers, resulting in less work for the user programs. Some programs may use only argument parsers exported by libraries, thereby achieving consistent and efficient option-parsing for abstractions implemented by the libraries.