From: Eric Armstrong <Eric.Armstrong@...>
Date: 2006-08-01T12:51:52+09:00
Subject: Re: Loop Timing and Constant Input

Picklegnome wrote:
> 
> how can I get input from the keyboard without the user pressing enter?
 >
For a platform independent operation, I recently
began investigating "Curses":

   require 'curses'
   include Curses

operations to play with:
    clear   -- clear the screen
    addstr  -- append text to the buffer
    refresh -- display the text in the buffer
    getch   -- get a character
               (compare to ?x, for example, to
                test for the letter "x")

I have a getting-started template, but neglected
to push it to the web. Ask me again tomorrow...

So far, I've found two problems with curses:

   a) There doesn't seem to be any equivalent for the
      windows Kbhit. That's the nice little operation
      that lets you ask whether there is a character
      in the buffer, and proceed if there isn't any.

   b) Examining the Curses API at
      http://www.ruby-doc.org/stdlib/, I found what
      can only be described as an embarassing lack of
      commentary. Not even one word! And since it's
      a wrapper, the implementation code is of no help.
      (And curses isn't even mentioned here:
      http://www.rubymanual.org/list/classes)

      I can only assume that some form of standard
      operational documentation exists on the web.
      If so the API doc should point to it, at least.
      (It's difficult to find, assuming it exists,
      because of all the references to NCURSES. That
      seems to be good, but the APIs are a wrapper
      for an ncurses.lib, which raises the ugly spectre
      of installation issues in my non-standard
      location. When I tried that with htree, I got
      horrible ".so" not found errors that no one
      could help with--so I abandoned htree for another
      day.)

Searching on "curses API", I did find these papers:

Curses in Python
http://aspn.activestate.com/ASPN/docs/ActivePython/2.3/howto/curses/curses.html

Tutorial on Python Curses Programming
http://heather.cs.ucdavis.edu/~matloff/Python/PyCurses.pdf

On my solaris box there is also man page for curses,
but it lists dozens of APIs that aren't in the ruby 
library--and to find out what they do, you have to look
them up individually.

Still, *nix users have a way to find out what the
APIs are expected to do. Windows users are SOL, unless
someone can point me to a good man-page => html conversion
tool. (The utility I wrote goes in the other direction,
unfortunately.)