From: "ara.t.howard" <ara.t.howard@...>
Date: 2008-05-08T01:32:12+09:00
Subject: Re: Getting pipe return codes from SYSTEM command


On May 7, 2008, at 9:50 AM, Russell Quinn wrote:
> Thanks for the reply. But there is a pipestatus array in bash isn't
> there?
>
> ls | foo
>
> echo ${PIPESTATUS[0]}
>
> see:
> http://aplawrence.com/Blog/B955.html
>
> I just couldn't get it to work from Ruby
> --  


that's because you've lost the bash process by the time bash exits.   
use my session gem if you want a persistent bash session against which  
to run commands:

require 'session'

bash = Session::Bash.new

stdout, stderr = bash.execute 'ls | grep something'
p bash.status

stdout, stderr = bash.execute 'echo ${PIPESTATUS[0]}'
p bash.status

etc.  session uses a *single* bash session for all it's commands so  
you can do this sort of thing.  however i'm not sure what the point is  
when pipelining from ruby, without shelling out, is so easy?

regards.

a @ http://codeforpeople.com/
--
we can deny everything, except that we have the possibility of being  
better. simply reflect on that.
h.h. the 14th dalai lama