|Copyright © 2000-2016 Thibault Godouet||Fcron 3.3.0 (dev release)||Web page : http://fcron.free.fr|
|Prev||Chapter 1. Fcron: how and why?||Next|
Fcron is a scheduler. It aims at replacing Vixie Cron, so it implements most of its functionalities.
But contrary to Vixie Cron, fcron does not need your system to be up 7 days a week, 24 hours a day: it also works well with systems which are not running neither all the time nor regularly (contrary to anacrontab).
In other words, fcron does both the job of Vixie Cron and anacron, but does even more and better :)) ...
To do so, fcron allows you to use the standard mode in which you tell it to execute one command at a given date and hour and to make it run a command according to its time of execution, which is normally the same as system up time. For example:
and, of course, in order to make it really useful, the time remaining until next execution is saved each time the system is stopped. You can also say:
Run the task 'save /home/ directory' every 3h15 of system up time.
which will be done if the system is running at any time in this interval.
run that command once between 2am and 5am
Fcron also includes a useful system of options, which can be applied either to every lines following the declaration or to a single line. Some of the supported options permit to:
run jobs one by one (fcrontab option
set the max system load average value under
which the job should be run (fcrontab option
set a nice value for a job (fcrontab option
run jobs at fcron's startup if they should
have been run during system down time (fcrontab option
mail user to tell him a job has not run and why
a better management of the mailing of outputs ...
a Linux/Unix system
Fcron should work on every POSIX system, but it has been developed on Mandrake Linux (so it should work without any problems on Redhat).
Fcron has been reported to work correctly on:
Linux Debian 3.0
(take a look at the Beyond LFS book to find the installation informations).
but fcron should work on other OS as well. Yet,
if you have troubles
making it work on a POSIX system, please
contact me at
<<fcron at free dot fr>>.
a running syslog (or you won't have any log)
a running mail system ( sendmail or postfix for example) (or users will not able to read their jobs output)
(optional) a PAM library.
(optional) a system with a working SE Linux environment.
Please send me the description of any bug you happen to encounter
(with, even better, the corresponding patch -:) and any propositions,
congratulations or flames at
<<fcron at free dot fr>>
Please contact Russell Coker directly for problems about SE Linux support at
<email@example.com>, since he maintains this part of the code.