Re: vc scrollback

Michael K. Johnson (
Tue, 17 Oct 1995 16:06:31 -0500

Dan Merillat writes:
> I'd like vc hooks in the kernel, and a user-space way to use them.
>keep the VC system the way it is, but allow a user process to modify
>the kernel vc table. And to those who mentioned using screen on
>a single local console... bleaguh! alt-f1 through ctl-leftalt-shift f12
>is much nicer. BUT:
>if there were hooks in the kernel for it, then a dumb-terminal on
>the serial port could be sending _IT'S_ alt-f1 sequence, and pulling
>a vc that way. (perhaps like screen does, ttyq etc.)
>besides, X needs the vc's as is, and I'm sure that everyone would
>_LOVE_ to have to recompile their x server to do the switching itself.
>So, internal stays as is, but how about: select_vc(), etc. that
>can be used as well as the internal alt-fkey hooks.

It might make sense for you to look into the implementation before
suggesting "changes". You have just suggested that VCs be changed
to ack like they already do...

The kernel changes VCs on its own *only* if no application has
requested to control changing either to the VC in question or
from the current VC. Otherwise, the app(s) requesting control
have control.

Read my series of articles in issues 3 and 4 of Linux Journal
on Programming the VT Interface if you want more details.