CODEWITHSUNDEEP
haskellcommand-line-arguments
Leif Grele
Leif Grele

Reputation: 223

Handling command line options with multiple arguments for some flags

I'm writing a program where the command line usage should be something like:

mkblueprint FILE FILE FILE -o <output name> -s <string> -r <number> -p pOPT1 pOPT2 pOPT3

I'm currently using CmdLib and I can't figure out a way to handle this; a flag is required for each input(so I can't just have FILEs sitting alone) and there doesn't appear to be a way to pass multiple arguments to a flag, as with -p. These are extremely common in command line programs so I figure I'm just misunderstanding the documentation, but it's not mentioned in any command line library I look at for Haskell.

Upvotes: 1

Views: 1097

Answers (2)

Leif Grele
Leif Grele

Reputation: 223

After some more work with CmdLib I was able to handle the bare FILE input via the Extra tag and then checking that each string is a valid file, which seems to be the standard way to handle it despite the name. -p pOPT1 pOPT2 pOPT3 is apparently not allowed under the POSIX standard, which is why I'm not finding libraries that will do it.

Upvotes: 1

Daniel Wagner
Daniel Wagner

Reputation: 152707

You might consider the GetOpt bindings that come with base. They're not as sexy as some of the more modern alternatives, but they support bare arguments and final options well.

Upvotes: 0

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