From: patrick-may@... (Patrick May)
Date: 2002-08-18T17:23:18+09:00
Subject: Re: How do I dup file descriptors in ruby?  (diverting STDERR)

Richard Ryan <ryanr@12-253-103-174.client.attbi.com> wrote in message news:<m2sn1dkzox.fsf@12-253-103-174.client.attbi.com>...
> Thanks for the suggestion.  The problem with metaphor is that the
> intended idea can be too easily miscommunicated.  By ``symphony''
> I was referring to the complexity of the code structure.

If by complexity you mean not calling the same function 6 times with
different args, then by all means continue using your prefered tool:

exec 3>&1
exec 4>&2
exec 1> /tmp/logfile.out 2>&1
# ... do stuff
exec 1>&3
exec 2>&4
exec 3>&-
exec 4>&-

> Anyway, that being said, if you put the merging of stdout together
> with stderr into the logfile which is in my second example, you'll
> probably get back at least the same number of lines, and you'll still
> have the complexity (if not quite a bit more).

True, the simplist ruby example:

err = $stderr
out = $stdout
open( "logfile.text", "a" ) do |file|
    $stdout = $stderr = file
    # ... do stuff
end
$stderr = err
$stdout = out

However, if this is a common operation for you, Ruby allows you to
improve on the above by abstracting the functionality and letting you
pull it in.  That's what the require 'redirect' solution is about.

>  Also, please keep in
> mind that I am thinking of putting a significant amount of code inside
> of the redirection and merging---I would definitely like to avoid the
> extra block if at all possible.

Which block is extra, and what is wrong with it?

> Also, please note that in my second
> example I ``un-merge'' stdout from stderr when I'm done.

so have all the examples

~ Patrick