From: "Ara.T.Howard" <ahoward@...>
Date: 2004-04-24T00:24:06+09:00
Subject: Re: Talking with processes

On 23 Apr 2004, Dario Linsky wrote:

> Hi,
> 
> I am trying to open an external process that normally reads and writes from 
> stdin/to stdout. For opening a pipe to this process I am using IO.popen.
> 
> Reading each line from the pipe is no problem until it comes to a point where 
> the external process wants to get some data from stdin and it waits for input.
> 
> Now when I write something into the IO stream I need to call IO#close_write for 
> further reading. But since the pipe is closed now, I cannot write to it any 
> more.
> 
> For example:
> -- snip --
> pipe = IO.popen("ruby -r debug script.rb", "w+")
> if pipe
>   while line = pipe.gets
>     line.chomp!
>     puts line
>     if line =~ /^script\.rb:\d+\:.+$/ # Regexp to find special lines
>       # Here I want to tell the debugger what to do and
>       # get further output to evaluate.
>       pipe.puts "next"
>       pipe.close_write
>   end
> end
> -- snap --
> 
> Is there any way to reopen the pipe at the position where I close it or is there
> any way to avoid using IO#close_write so I can write more commands to the 
> debugger?
> 
> Greetings, Dario
> 


try this:

  http://raa.ruby-lang.org/list.rhtml?name=session

it will do that, and more.  what you describe is EXACTLY why i wrote this,
when you need to send muliple commands to an external process and de-multiplex
the responses (output).  you also get stderr.

-a
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