[Haskell-cafe] Re: Re: A question regarding cmdargs package

Ben Franksen ben.franksen at online.de
Tue Oct 12 18:53:02 EDT 2010

Neil Mitchell wrote:
>>> This makes me curious.  What's the use case where you want to allow the
>>> user to pass arguments on the command line, but you don't want that user
>>> to be able
>>> to use '--help' to find out what arguments may be passed?

I wanted to create a clone of an existing program that had no help option
and instead gave the help output if it saw an invalid option.

>> When you don't want to bother defining the help options/descriptions? :p
>> (alternatively, you may wish to provide a more full-featured version
>> like what darcs does by using a pager)
> You can already do this with CmdArgs. If you use cmdArgsMode/process
> it returns a structure populated to say what to do next (i.e. display
> a help message), but you are welcome to do something different, or do
> what it says in a different way. However, I can see some people might
> want to remove help entirely, so I'll try and find a balance.

The point here was not so much removing --help, but rather that I want to
have control over the 'standard' options (help,version,verbosity) in the
same way as for the rest. My program might not have a version, so why
offer --version? Or maybe I want a different name for it because the -V is
already used for something else, which I cannot change for backwards
compatibility. I might want another name for --help, for instance -h. The
standard -? does not work in all shells/configurations and --help might
look strange if all other options are of the one-dash-one-character sort. I
would also like to configure the help text for the standard options, for
instance for i18n or because I like starting with a lower case letter or...


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