From: Paul Brannan <pbrannan@...>
Date: 2001-11-14T00:31:26+09:00
Subject: [ruby-talk:25017] Re: changing the shell used by 'system'

On Tue, 13 Nov 2001, Joel VanderWerf wrote:

>
> Is it possible to determine what shell Ruby is going to use for spawned
> commands?

Ruby tries to do the best it can to determine whether it is possible to do
a simple fork+exec of the process, and if it can, then it will.  That is,
if you do:

  system("rm -f foo")

then Ruby will call fork() and it will then exec() /bin/rm.  However, if
you do:

  system("ls > foo")

then Ruby will call fork() and it will then exec() sh -c "ls > foo",
because of the special character '>'.  This, of course, appears to be
completely system-dependant, so I don't recommend depending on its
behavior if you can avoid it.  A much better solution would be to use
Kernel#fork and Kernel#exec yourself, or to use IO#popen.

Paul