From: Phlip <phlip_cpp@...>
Date: 2002-09-01T15:38:00+09:00
Subject: beating features out of popen

Rubies:

I downloaded and installed a command-line Mancala game:

 http://ibiblio.org/pub/Linux/games/strategy/mancala-1.0.0.tar.gz

Being in C, it has only a console user interface, and an attempt at an 
xforms user interface. Yuch.

So I feel like throwing a TkCanvas on top of it. But the first hurdle is to 
connect to the mancala executable via full duplex pipes. Yuch.

My feeb attempt, and the Lapidary (sorry) testage for it are below my sig. 
It works (so far) but looks hideous. Yes, I tried popen3 - it simply 
projected twice as many bugs into the space. The fix I finally got working 
lets an exception throw in lieu of detecting "end of stream". Yuch.

Does anyone have any tips how to crack the vault that is the POSIX "open" 
standard?

-- 
  Phlip
                http://andstuff.org/HarryPotter
  --  Why is the "Cheesy Horror Movie Channel" called "SciFi"?  --


#!/usr/bin/env ruby

require 'tk'
require 'fcntl'
require 'trace'
require 'open3'


class Mancala

    def initialize
        @canvas = nil
        @top = nil
        @boardString = nil
    end

    def makeCanvas
        @top = TkRoot.new { title "Mancala" }
        
        @canvas = TkCanvas.new (@top) {
                    grid 'row'=>0, 'column'=>0, 'sticky'=>'nsew'
                    background '#aaaaaa'
                    width 800
                    height 600
                    }
    end
    
    def getBoardString
        return @boardString
    end

    def pipeMancala
        'Did this have to be so fucking hard?'
        
        pipe = IO.popen( "mancala 0", "r+" )
        pipe.close_write()
        pipe.fcntl(Fcntl::F_SETFL, Fcntl::O_NONBLOCK)
        @boardString = ''

        loop do
            begin

    #  TODO  feel a scrap of guilt about using exceptions
    #        to define normal control flow. And about throwing
    #        away the exception type
            
                contents = pipe.gets()
            rescue
                break
            end
        
#            print contents
            @boardString += contents
            break if @boardString.size() > 159
        end

#       trace_{@boardString}
    end
      

    def destroy
        @canvas.destroy() if @canvas != nil
    end

end



----8<-------------------------------------

#!/usr/bin/env ruby

require 'Lapidary/TestCase'
require 'Lapidary/UI/GTK/TestRunner'
require 'Lapidary/UI/Console/TestRunner'
require 'mancala.rb'


class TestMancala < Lapidary::TestCase

    def setup    
        system 'killall mancala'  #  TODO  yank this hack out
        @aBoard = Mancala.new()
    end

    def test_makeCanvas
        @aBoard.makeCanvas()
#        Tk.mainloop
        @aBoard.destroy()
    end

    def test_pipeMancala
        @aBoard.pipeMancala()
        bs = @aBoard.getBoardString()
        
        assert bs == '''    f: 4 | e: 4 | d: 4 | c: 4 | b: 4 | a: 4
  0 -----+------+------+------+------+-----  0
    a: 4 | b: 4 | c: 4 | d: 4 | e: 4 | f: 4

'''

# Move for player at top: '

    end

    def tearDown
        puts 'tearing down'
        
        @aBoard.destroy()
    end

end


class TS_Mancala
    def TS_Mancala.suite()
        suite = Lapidary::TestSuite.new()
        suite.add TestMancala.suite()
        return suite
    end
end

def main
#       Lapidary::UI::GTK::TestRunner.run(TS_Mancala)
        Lapidary::UI::Console::TestRunner.run(TS_Mancala)
end

main
# Tk.mainloop