From: Gennady <gfb@...>
Date: 2003-11-25T07:27:00+09:00
Subject: Re: Exit status on cmd executed via popen()

Try variable $?, it holds the status of the last executed command. Works 
for commands executed with 'system', I think it is valid for popen as well.

Gennady.

Garance A Drosihn wrote:
> Sometimes I write ruby scripts to filter the output of some
> other command.  So I write something like:
> 
> cmdout = IO.popen(somecmd, "r")
> cmdout.each_line {|aline|
>     #  Do Stuff...
> }
> cmdout.close
> 
> Is there any way to find out what the exit status was from
> the command given to popen?  It would be nice to have some
> method that I could use like:
> 
> if cmdout.popen_exit_status != 0
>     #  Do Error-processing stuff
> end
> 
> which could be done after reading all the lines, but before
> the call to 'close'.
> 
> Or do I need to do something more complicated than 'popen'
> if I need to know the exit code from that command?
>