fmt: Error priorities could be improved

[BenWiederhake]

$ fmt -g apple -g7 tests/fixtures/fmt/one-word-per-line.txt
this is a
file with one
word per line
$ fmt -g apple -g7 -w banana tests/fixtures/fmt/one-word-per-line.txt
fmt: invalid width: 'banana'
[$? = 1]
$ fmt -g apple -w banana tests/fixtures/fmt/one-word-per-line.txt
fmt: invalid width: 'banana'
[$? = 1]
$ fmt -w apple -g banana tests/fixtures/fmt/one-word-per-line.txt
fmt: invalid width: 'apple'
[$? = 1]

This means:

• A non-numeric value for a numeric argument is okay IF it is later overridden by a numeric argument.
• --width-related errors take priority over --goal-related errors, no matter the order.

I have some questions:

• To what extent do we want to be error-message compatible?
• This probably affects other utils, too. What's our standpoint, in general?

[tertsdiepraam]

"Terrible" is not support helpful 😄 Do you mean GNU or uutils here? We could do this quite easily, by supporting a string and then passing them after argument parsing.

[BenWiederhake]

Oh, sorry! I meant GNU, as in "This is terribly difficult to match".

re parsing: Oh! I only now notice that the error message is indeed simple enough. Dips!