Re: [gentoo-portage-dev] PATCH: Disable logging during pkg_config (#99527)

[Drake Wyrm]

Jason Stubbs <jstubbs@g.o> wrote:
> On Wednesday 20 July 2005 15:38, Drake Wyrm wrote:
> > Jason Stubbs <jstubbs@g.o> wrote:
> > > When logging is enabled, ebuild output is passed via tee. Running
> > > anything that checks for terminal type inside of pkg_config
> > > therefore doesn't work correctly. This patch disables logging
> > > during pkg_config altogether.
> >
> > A cleaner way of accomplishing that is to write the ebuild such that
> > portions which need a terminal either attach to a terminal (`make
> > menuconfig </dev/tty >/dev/tty`)
>
> Forgive my ignorance, but how does this work when it comes to
> multiuser?

You mean when there's multiple terminals in use? The device "/dev/tty"
has more magic. No matter what terminal you're using, even if stdin,
stdout, and stderr have been closed or redirected, "/dev/tty" is
_always_ your current terminal.

	{ echo foo >/dev/tty ; } </dev/null &>/dev/null

Still gets through! Or even more detached:

	( ( sleep 2 ; echo foo >/dev/tty ) & disown ) </dev/null &>/dev/null

The only way this can fail is if the terminal actually closes.

	( ( sleep 2 ; echo foo >/dev/tty || touch /tmp/wombat ) & \
	disown ) </dev/null &>/dev/null ; exit

Other apps use this, also. You may have noticed that when you drop to
shell from `less` and type `tty`, you're no longer attached to
/dev/pts/* or /dev/vc/*, but simply to /dev/tty. Do the same thing in
multiple xterms, and you'll find yourself with several terminals all
attached to unique instances of /dev/tty which have nothing to do with
each other. More magic.

-- 
Batou: Hey, Major... You ever hear of "human rights"?
Kusanagi: I understand the concept, but I've never seen it in action.
  -- "Ghost in the Shell", Shirow Masamune