From: "Ara.T.Howard" <ahoward@...>
Date: 2004-05-15T03:53:53+09:00
Subject: Re: getc windows != linux

On Fri, 14 May 2004, Roeland Moors wrote:

> I'm trying to communicate with a program (gnucap) using ruby.
> 
> The versions of ruby (1.8.1) and gnucap (0.34) are the same on windows 
> and linux.
> 
> When I start gnucap, this is the output:
> 
> Gnucap 0.34
> The Gnu Circuit Analysis Package
> Never trust any version less than 1.0
> Copyright 1982-2002, Albert Davis
> Gnucap comes with ABSOLUTELY NO WARRANTY
> This is free software, and you are welcome
> to redistribute it under certain conditions
> according to the GNU General Public License.
> See the file "COPYING" for details.
> gnucap> _
> 
> 
> 
> Here is a simple ruby test program:
> 
> <-- CODE -->
> #!/usr/bin/env ruby -w
> 
> gnucap = IO.popen("gnucap", "w+")
> output = ""
> while output !~ /.*#{"gnucap>"}$/
>      char = gnucap.getc.chr
>      output += char
> end
> puts "ok"
> <-- CODE -->
> 
> In Linux this program works and shows me "ok". But on windows the 
> program stops reading after the last newline: "...details."
> This means the program never reach ok.
> It keeps waiting for input.
> 
> Any ideas or suggestions?
> 
> Thanks

the output from gnucap on window must be line buffered - because it hasn't
sent a newline the last line with 'gnucap> ' on it has not been flushed and is
not available for reading.  i bet that, if you ran a few hundred times, you'd
see this behaviour with linux too.  i dont know if

  gnucap.sync = true

will work

if not perhaps you could write alittle wrapper like this

file: wgnucap.rb
==============
#!/usr/bin/env ruby
STDOUT.sync = true
STDERR.sync = true
cmd = 'gnucap ' + ARGV.join(' ')
exec cmd

though i don't really know about windows...
  
-a
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