setting env vars

[David A. Bandel]

On Mon, 10 Feb 2003 16:14:24 -0500 (EST)
Net Llama! <netllama at linux-sxs.org> wrote:

> On Mon, 10 Feb 2003, Condon Thomas A KPWA wrote:
> > Net Llama! <mailto:netllama at linux-sxs.org> typed thusly on Monday,
> > February 10, 2003 12:40 PM:
> >
> > > On Mon, 10 Feb 2003, David A. Bandel wrote:
> > >> Remember all those daemons running on your system?  Some
> > >> of them need the information provided by these files and
> > >> these daemons have no "environment".  So where will they
> > >> get the right info from?
> > >>
> > >> Since the info doesn't change, I suggest you get the
> > >> address and name during bootup and put the correct info
> > >> in the file.
> > >
> > > Unfortunately, its not quite that simple.
> >
> > Couldn't you set up the environmental variable in the
> > /etc/rc.d/rc.sysinit file (or whatever file is executed first by
> > init reading /etc/inittab) and export it.  It would then be
> > available to *all* of the daemons that init kicked off, as well as
> > later applications.  It would also be modifiable, too, wouldn't it?
> 
> According to Dave Bandel, that wouldn't work.

when you EXPORT a variable, it's available to CHILD processes, not
PARENT processes.  So the KERNEL, which runs init, would have to have
that variable set (which it can't) in order for init to have it.  Since
init has no exported variables, its CHILDREN have none.  init runs
rc.sysinit, but as soon as rc.sysinit exits, the exports are gone and
init knows nothing about them.

Think about it for a while, you really want this to be the way things
work.  Because if you could assign a changeable environment to init,
_anyone_ could change the environment and do as they pleased.  UNIX has
seen its share of faux paux like this in the kernel (thankfully, those
have long since been removed).

If I understood more of what Lonnie needs to do, there might be a way,
but he's been rather cryptic about it so it must be a secret.

Ciao,

David A. Bandel
-- 
Focus on the dream, not the competition.
		Nemesis Racing Team motto
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