unversal watchdog

[M. Warner Losh]

In message: <20060228042626.GA35526 at stupid.rinet.ru>
            Alex Semenyaka <flist at jabberwock.rinet.ru> writes:
: On Mon, Feb 27, 2006 at 05:41:32PM +0700, Vitaliy Ovsyannikov wrote:
: > Hello, freebsd-hackers.
: >   I've stuck with the unable to make watchdogs for daemons running via
: > startup rc-scripts. In linux we can just put the process in the
: > inittab. Does FreeBSD contains ability like this?
: 
: You can do it with /etc/ttys. Actually this point is missing by many
: FreeBSD administrators, people just think of /etc/ttys in term of
: terminals and stuff :) But if youi'll open the man page you would
: found the following:
: 
:      The first field is normally the name of the terminal special file as it
:      is found in /dev.  However, it can be any arbitrary string when the asso-
:      ciated command is not related to a tty.
: 
: So you can perfectly run any program there and init will watch or it, just
: like in linux.

The behavior goes back to at least 4.2 BSD (not FreeBSD 4.2, but 4.2
BSD).  I've used it on old SunOS 3.x boxes too...

Warner