Anybody can feel free to edit and expand this page. Please remove the needs_attention tag if you have added useful information about the topic and remember to credit yourself in the Sources section… — Harishankar 2012/08/31 04:31

I have added the task of writing pages for cron, at and anacron to my task queue, I will hopefully get them completed soon. — Matthew Fillpot 2012/12/24 21:26

Slackware uses dcron, which can be used for asynchronous cron.

From dcron README, “In the author's opinion, having to combine a cron daemon with another daemon like anacron makes for too much complexity. So the goal is a simple cron daemon that can also take over the central functions of anacron.”

It uses the notation @freq, eg. @hourly, @daily, etc, or the notation FREQ=, eg FREQ=1h, FREQ=1d, etc. (see man 1 crontab)

The daily cron job, as found in Slackware's root crontab is

# Run daily cron jobs at 4:40 every day:

40 8 * * * /usr/bin/run-parts /etc/cron.daily 1> /dev/null

which, for a host that is not continuously on, can become

# Run daily cron jobs whenever crond is running, and sees

# that at least one day has elapsed since it last ran

@daily ID=cron_daily /usr/bin/run-parts /etc/cron.daily 1> /dev/null

Let it be noted that it works equally well at a cold boot or a resume from suspend or hibernate.

—pdi 2016/01/05