[clue-tech] using screen as init

[Jim Ockers]

Hi Michael,

> On Fri, 2006-11-10 at 10:05 -0700, Jim Ockers wrote:
> > We have to do something like this so one can log in and have a look at
> > a GUI curses app that runs at startup on the console and which requires
> > user interaction.  Of course the system is headless and has no key-
> > board, and the only way to talk to it is over the network.
> 
> Why not run an init script that starts up screen that then starts the
> curses app.  This would be simpler than trying to replace init with
> screen and running init inside of screen.  You could run even run the
> screen launching utility on a VT in inittab (instead of running it as an
> init script).  That has the advantage of restarting the utility should
> the curses app exit.

Thanks for the interesting idea, I'm intrigued by it.

The curses app exists because it may be necessary to interrupt the boot-up
process if there is something wrong that needs user intervention.  This
code is legacy from a different system that did have a keyboard &
monitor, but is very complex so we don't want to rewrite it.

The curses app has to run fairly early in the boot-up sequence; the mounting
of non-root filesystems actually could be interrupted or delayed based on
the error condition, and can only proceed if the error condition is cleared
(or can't proceed if not cleared).

I guess I'm not familiar enough with init to know how to make the init
script that runs the curses app but which runs at the same level & time
as the rcS sysinit stuff.

Could you please suggest a bit more detail about how to accomplish this
in the way you suggest?

Thanks,
JimO

-- 
Jim Ockers, P.Eng. (ockers at ockers.net)
Contact info: please see http://www.ockers.net/