From: Carlos <angus@...>
Date: 2002-08-22T04:44:42+09:00
Subject: Re: inconsistency in shared state between parent/child processes

> i am very confused about how/when global state is shared between
> parent-child processes in ruby, look at the following :

...
> $stderr = DupIO.new $errlog0
...
> # this is NOT!!!
> `ls some/command/which/produces/stderr`

...
> $stderr = $errlog1
...
> # this is TOO!!!
> `ls some/command/which/produces/stderr`

Because when you assign $stderr or $stdout to a IO object, Ruby does some
magic and dups the file descriptor. But when you assign it to some other
object, it only changes the binding of the variable; and everything that
goes to stderr or stdout by other meanings than calling methods... well,
goes to stderr or stdout.