[texdoc] Some small bugs and more

[Karl Berry]

Hi Takuto,

    I think it is better to print usage text instead of this.

Certainly agreed about the argument parsing fix (thanks!), but I think
it would actually be better for texdoc to report something like:

  texdoc: option '--just-view' requires an argument
  Try 'texdoc --help' for more information.

instead of printing the entire usage message. (I think texdoc currently
prints the whole usage message in other such cases too, where I think it
would be better to just report the error as above.)


I'm not sure if you were thinking of:

    > Searching by macro name???

FWIW, I can't imagine any viable way to implement this. It would amount
to a full-text search (and parsing) of the entire TL tree, code and
documentation, including decoding PDFs, etc. This seems rather beyond
the scope of texdoc.

    >     - http://tug.org/pipermail/tex-live/2010-May/025832.html

Scott's hack of extracting \DescribeMacro is interesting, but those are
just a small subset. I somewhat think it would be worse to implement
such a limited function than not having anything.


On the other hand:

    I thought that if texdoc has a function like "fuzzy search", 

That sounds great to me. If you have ideas for how to do fuzzy matching
on the existing database of filenames/package names/etc., by all means,
go for it! --thanks, karl.