ungetty

[Chip Rosenthal]

In article <6 at rsoft.UUCP> frank at rsoft.UUCP (Frank I. Reiter) writes:
>Can anybody tell me how ungetty interacts with getty or point me at a good
>source of information?

As far as I know, the interface is undocumented.  But, I believe signals
SIGUSR1 and SIGUSR2 are used to communicate between /usr/lib/uucp/ungetty
and /etc/getty.  Reading between the lines, when you call ungetty with a
tty device, it looks in /etc/utmp for the PID of the getty on that line,
and then does a kill() to signal the getty to either suspend or resume.
Note that ungetty is a setuid program, which is required for the kill()
to work.
-- 
Chip Rosenthal     chip at vector.UUCP    |      Choke me in the shallow water
Dallas Semiconductor   214-450-5337    |         before I get too deep.