Hello! I'm trying to use Monit to monitor my crond (on Slackware-current). It tries to use the standard /var/run/cron.pid. But I don't have such file on my system and the PID of the crond isn't recorded anywhere. I can always use something like that (but much more complex):
pidof crond > /var/run/cron.pid
I can recompile it too. But I want to figure out why doesn't dcron (that's the package for Slackware) have the cron.pid file and avoid recompiling (I think I should outsmart the defines in defs.h). Thanks in advance!

I don't think recompiling will help as I don't think creating a pidfile is an option.
But maybe you could modify the start script in /etc/rc.d/rc.M by adding your line:

# Start crond (Dillon's crond):
# If you want cron to actually log activity to /var/log/cron, then change
# -l10 to -l8 to increase the logging level.
if [ -x /usr/sbin/crond ]; then
/usr/sbin/crond -l10 >>/var/log/cron 2>&1
pidof crond > /var/run/cron.pid
fi

the pidfile would get stale if cron died unexpectedly, but then presumably Monit would alert you to that?
maybe worth a try anyway

tobyl