Fcron
Fcron's author is aiming at replacing Vixie Cron (the "normal" cron). Accordingly it implements most of its functionalities.
Fcron's main strength, though, is that a computer system need not be up 7 days a week, 24 hours a day like a server. Besides being useful on servers for its extra features fcron also works with systems which are not running all the time nor running regularly (contrary to anacron).
Fcron can run in standard mode (like the "normal" cron) executing one command at a given date and hour, i.e. to make it run a command according to its time of execution (normally the system time). So one can instruct it to run a task like 'save /home/ directory' every 1h30 of system up time. The time remaining until next execution is saved each time the system is stopped.
You can also assign it to run a given command once between 2am and 5am which will be done if the system is running at any time in this interval at all.
Fcron also includes a system of options, like:
- run jobs one by one (fcrontab option serial)
- set the max system load average value under which the job should be run (fcrontab option lavg)
- set a nice value for a job (fcrontab option nice)
- run jobs at fcron's startup if they should have been run during system down time (fcrontab option bootrun)
- run jobs after a specified delay after boot up
- mail user to tell him a job has not run and why (fcrontab option noticenotrun)
- a management of the mailing of outputs
- ...
Fcron can be found here: http://fcron.free.fr/ and the original documentation is at http://fcron.free.fr/doc/en/index.html. It comes with examples for a fcrontab and guidelines how to set it up.