From: ara.t.howard@...
Date: 2006-01-03T23:31:53+09:00
Subject: Re: Help on I/O pipe

On Tue, 3 Jan 2006, Sky Yin wrote:

> One process of my analysis program uses an external non-linear optimizer.
> That optimizer needs a model file as the argument. The current approach I
> employ to accomplish this is to create a model file on disk everytime
> running the optimizer. The code is simply like
>
> @model = File.open("model.mod", "w")
> ...
> @model.close
> result  = `optimizer.exe model.mod`
>
> The problem is that I have to repeat running optimizer on different models
> many many times during the analysis. I wonder if such heavy writing on a
> single file will do any harm to my hard disk. My concern of improving it is
> to use I/O pipe to feed the optimizer without the needs to create real model
> files. Can anyone give me some tips or examples on using the shell pipe? The
> rdoc isn't so clear.
>
> Thanks

assuming that your analysis code can read it's input sequentially you might
want to try session:

   require 'session'

   sh = Session::new

   model_input = ...

   stdout, stderr = sh.execute 'optimizer.exe', 'stdin' => model_input

   p sh.exitstatus

regards.

-a
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