Re: [9fans] Namespace inheritance between processes

[Anthony Martin <ality@pbrane.org>]

Anthony Martin <ality@pbrane.org> once said:
> Casey Rodarmor <casey@rodarmor.com> once said:
> > Also, whatever the answer is, how can I test this for myself? I was
> > struggling to come up with a combination of commands, short of writing
> > some C programs, which would let me have two interactive rc shells
> > that inherit from one another, since rc doesn't have job control and
> > new rio windows are in a new process group.
>
> In one rio window, do the following:
>
>   % mkdir -p /tmp/wsys
>   % mount $wsys /tmp/wsys 'new -r 0 0 512 512 -pid '$pid
>   % { rc -i <>/tmp/wsys/cons >[1=0] >[2=0] } &
>
> Any further changes to the namespace will be reflected in both windows.

I was playing around with this a bit more and I came
up with something a bit cleaner. The following command
will create an interactive shell in a new window that
shares the namespace of it's parent and acts like a
normal rio window (as much as possible).

Cheers,
  Anthony

#!/bin/rc

rfork e

mkdir -p /tmp/wsys
mount $wsys /tmp/wsys 'new -r 0 0 640 480 -pid -1'
{
	rc -i </tmp/wsys/cons >/tmp/wsys/cons >[2=1] &
	rcpid = $apid
	echo set -pid $rcpid >/tmp/wsys/wctl
	echo -n rc $rcpid >/tmp/wsys/label
	wait $rcpid
	echo delete >/tmp/wsys/wctl
} &