Description of problem: This line appears in freshclam-sleep, a Fedora script: sleep $[ (FRESHCLAM_DELAY % FRESHCLAM_MOD + FRESHCLAM_MOD) % FRESHCLAM_MOD ] This line is equivalent, and is easier to read: sleep $[ FRESHCLAM_DELAY % FRESHCLAM_MOD ] Additionally, since cron executes jobs in parallel, there's no reason to have FRESHCLAM_MOD in any of the files. It could be removed from sysconfig/freshclam and freshclam-sleep entirely with no detrimental effects. Users might notice that there are multiple freshclam-sleep jobs sleeping at any given time, but that won't cause any problems, and simplifies configuration. As it is, users may still see that if they adjust the cron schedule and not FRESHCLAM_MOD.
Won't change it. Mentioned line is due to | $ d=-5 | $ m=10 | $ echo $[ d % m ] | -5 | $ echo $[ (d % m + m) % m ] | 5 FRESHCLAM_MOD must stay as FRESHCLAM_DELAY is calculated from 'hostid' which returns a 32 bit number.