> I agree that your script is nice and simple, and hence less prone to
> errors. I coded mine in c++ because I use it not only for a machine
> type watchdog, but also a task based watchdog that reboots the machine
> based on certain tasks living or not. Each task has to register with
> the watchdog server and continually tell the server they're alive, or
> reboot! But that's a story for another thread...

  #!/path/to/perl

  use strict;

  use Sys::Syslog;

  open my $fh, '>', '/dev/watchdog'
  or die "/dev/watchdog: $!";

  # if any of these go away we need to notice it.
  # ok... you'll notice the first one anyway.

  my @watchz
  = qw
  (
    init
    ntpd
    apache
    /opt/sybase/ASE-12_5/bin/dataserver
  );

  # wd timeout / 2, or 1 for minimum sleep
  # (avoid usleep: too much overhead).

  my $cycle  = 15;

  # get the syslog handle

  openlog blah blah blah
  or die 'Et tu, syslog?';

  CYCLE:
  for(;;)
  {
    sleep ( $cycle - ( time % $cycle ) );

    # split and args vary by O/S, this works on linux.

    my @procz  = map { split /\s+/, $_, 6 )[5] } qx( ps a );

    my %chechz = ();

    @chechz{ @watchz } = ();

    delete @chechz{ @procz };

    if( %chechz )
    {
       # oops, current proc's don't include the
       # list of processes being watched.
       #
       # this can happen twice in a w/d interval
       # before the system goes down.

       my $nastygram
       = join "\t", 'Missing proc's:', join "\t", keys %chechz

       syslog LOG_CRIT | LOG_FOO, $nastygram;

       next CYCLE

       # alternative here is to close $fh here and
       # bounce the system immediately, the
       # approach of looping allows an
       # intentional restart of the service
       # (in less than 1 w/d cycle) w/o bouncing the box.
    }

    # if the proc check got this far then the w/d
    # file gets poked and we live for another loop.

    print $wd "\n";
  }

  # this isn't a module

  0

  __END__

--
Steven Lembark                             85-09 90th St.
Workhorse Computing                      Woodhaven, NY, 11421
lembark@(protected)
--
gentoo-user@(protected)