From: Marcin Raczkowski <mailing.mr@...>
Date: 2007-09-21T03:23:30+09:00
Subject: Re: Interactive System calls within Ruby Script

ZyLo wrote:
> I'm not sure whether this is possible or not, but I know that Ruby
> allows you to make system calls in many different ways, and I
> generally use:
> 
> system "echo Hello"
> 
> or something when I want to call outside of the script.  What I would
> like to know is if it is possible to make these system calls
> interactive?  For instance, I was toying with directory manipulation
> using system "cd .." system "pwd", etc., and I noticed that no matter
> what the call, Ruby will always return to the same directory on the
> system "pwd" command.
> 
> I was wondering if it is possible to send multiple commands so you
> could be a bit more interactive with it?  I know there are libraries
> out there to do this for me, but I am looking at this more from the
> standpoint that I'm not planning on using this ability for directory
> manipulation.
> 
> Another thing I was wondering is whether you can get output from the
> terminal on system calls.  I tried somethign like this:
> 
> system "pwd"
> gets directorystring
> puts directorystring
> 
> Only my script doesn't get the input at all, and hangs(expecting an
> input I assume).
> 
> How can you usefully use system for calling functions if it doesn't
> remember state(directory, for instance), or allow you to get back
> terminal information?
> 
> 
> 
use open4 gem