support command-line args

[alaniwi]

It would be good for xconv2 to accept command-line args. Unless I've missed something, it doesn't seem to at present.

A basic initial set might look like:

• some means of specifying data filename(s) to open when launching the app (whatever exact syntax you decide on)
• --help
• --version

Can add more later.

[bnlawrence]

The intention is for this to operate like an O/S gui (indeed, there is already a mac app), so they wouldn't typically have arguments, that said, I think there is a case for opening with a filename on the command line. (Both version and help are directly accessible from the GUI itself, do you really think they are necessary on the command line too?)

[jonnyhtw]

... that said, I think there is a case for opening with a filename on the command line.

FWIW big thumbs up for this ⬆️ in my opinion.

This is the standard way of opening stuff with the previous xconv, that is...

$ xconv /path/to/my/file.nc

Cheers.

Jonny