Re: /bin/sh fd 12

[Jan Schaumann <jschauma%netmeister.org@localhost>]

Robert Elz <kre%munnari.OZ.AU@localhost> wrote:

> When you redirect standard output of a built-in command, the
> existing standard output needs to be moved somewhere else (saved)
> before the new one can be opened (dup'd in this case).  13 is
> the next available fd

I see, thanks.

It looks like the selection of fd 12 happens in
jobs.c, setjobctl, #184 / redir.c #588 ff.

I gather the intention is to pick an fd that's above
10, because users might want to do other manual
redirections ("exec 3<whatever") and are likely to
choose small fd numbers.

So 13 really isn't the next _available_ fd (which
would be 3), but "the next available 'high' fd we
expect not to clash with any of the users' fds".

Do you want me to send-pr the redirection to fds
12/13?

-Jan