From: Tobias Reif <tobiasreif@...>
Date: 2002-05-29T18:04:00+09:00
Subject: Re: OS independent scripts, system calls on Windows and Linux

nobu.nokada@softhome.net wrote:

Hi,


> stdout/stderr are NOT exclusive.  What would be returned when
> both of stdout and stderr were outputted?


I see; thank you very much for constructive criticism.

Unfortunately I in no way have sufficient experience, skill, or 
knowledge to really help with the syntax, API, or implementation.

I need the following:


A very simple, (perhaps OO) way of writing batch/shell scripts in Ruby.
I need to be able to rely on the fact that it will run on any of the 
major platforms.

I want to get what the command returns; if possible, I'd like to know if 
there was any of stdout, stderr, or both, or nothing, so I can choose 
what to do with the returned strings/objetcs, or if to raise an error. 
Would that be feasible?

Syntax *could* look like (this probably has errors)

commands = Commands.new ['this -x -y','that -a -b']
commands.each do |cmd|
   returned = cmd.issue # or ".run", ".enter", ...
   # returned will hold a hash like
   # {}, or {:stderr=>'kabloom'}, or
   # {:stderr='minor error', :stdout=>'done.'}
   if returned[:stdout]
     puts returned[:stdout]
   elsif returned[:stderr]
     raise returned[:stderr]
   end
   # should be more OO:
   # the returned items are objects of class Stderr and ...
   # (something like that)
   # returned.inspect => [object_of_class_Stdout, object_of_class_...]
end

or

...
   if ret.stdout?
     puts retd.stdout.to_s
   elsif ret.error?
     raise ret.error.to_s
   end
...

Tobi


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