|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
|
ANACRONTAB(5) File Formats ANACRONTAB(5)
/etc/anacrontab - configuration file for Anacron
The /etc/anacrontab configuration file describes the jobs
controlled by anacron(8). It can contain three types of lines:
job-description lines, environment assignments, or empty lines.
Job-description lines can have the following format:
period in days delay in minutes job-identifier command
The period in days variable specifies the frequency of execution
of a job in days. This variable can be represented by an integer
or a macro (@daily, @weekly, @monthly), where @daily denotes the
same value as the integer 1, @weekly the same as 7, and @monthly
specifies that the job is run once a month, independent on the
length of the month.
The delay in minutes variable specifies the number of minutes
anacron waits, if necessary, before executing a job. This
variable is represented by an integer where 0 means no delay.
The job-identifier variable specifies a unique name of a job
which is used in the log files.
The command variable specifies the command to execute. The
command can either be a command such as ls /proc >> /tmp/proc or
a command to execute a custom script.
Environment assignment lines can have the following format:
VAR=VALUE
Any spaces around VAR are removed. No spaces around VALUE are
allowed (unless you want them to be part of the value). The
specified assignment takes effect from the next line until the
end of the file, or to the next assignment of the same variable.
The START_HOURS_RANGE variable defines an interval (in hours)
when scheduled jobs can be run. In case this time interval is
missed, for example, due to a power down, then scheduled jobs are
not executed that day.
The RANDOM_DELAY variable denotes the maximum number of minutes
that will be added to the delay in minutes variable which is
specified for each job. A RANDOM_DELAY set to 12 would therefore
add, randomly, between 0 and 12 minutes to the delay in minutes
for each job in that particular anacrontab. When set to 0, no
random delay is added.
If MAILTO is defined (and non-empty), mail is sent to the
specified address, otherwise, system user is used.
If MAILFROM is defined (and non-empty), it is used as the
envelope sender address, otherwise, system user is used.
(Note: Both MAILFROM and MAILTO variables are expanded, so
setting them as in the following example works as expected:
MAILFROM=cron-$USER@cron.com ($USER is replaced by the system
user) )
If NO_MAIL_OUTPUT is defined (and non-empty), the standard output
and error descriptors of job processes are not redirected and e-
mailed.
Empty lines are either blank lines, line containing white spaces
only, or lines with white spaces followed by a '#' followed by an
arbitrary comment.
You can continue a line onto the next line by adding a '\' at the
end of it.
In case you want to disable Anacron, add a line with 0anacron
which is the name of the script running the Anacron into the
/etc/cron.hourly/jobs.deny file.
This example shows how to set up an Anacron job similar in
functionality to /etc/crontab which starts all regular jobs
between 6:00 and 8:00 only. A RANDOM_DELAY which can be 30
minutes at the most is specified. Jobs will run serialized in a
queue where each job is started only after the previous one is
finished.
# environment variables
SHELL=/bin/sh
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
RANDOM_DELAY=30
# Anacron jobs will start between 6am and 8am.
START_HOURS_RANGE=6-8
# delay will be 5 minutes + RANDOM_DELAY for cron.daily
1 5 cron.daily nice run-parts /etc/cron.daily
7 0 cron.weekly nice run-parts /etc/cron.weekly
@monthly 0 cron.monthly nice run-parts /etc/cron.monthly
anacron(8), crontab(1)
The Anacron README file.
Itai Tzur ⟨itzur@actcom.co.il⟩
Currently maintained by Pascal Hakim ⟨pasc@(debian.org|
redellipse.net)⟩.
For Fedora, maintained by Marcela Mašláňová
⟨mmaslano@redhat.com⟩.
This page is part of the cronie (crond daemon) project.
Information about the project can be found at
⟨https://github.com/cronie-crond/cronie⟩. If you have a bug
report for this manual page, see
⟨https://github.com/cronie-crond/cronie/issues⟩. This page was
obtained from the project's upstream Git repository
⟨https://github.com/cronie-crond/cronie.git⟩ on 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2024-05-31.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
cronie 2012-11-22 ANACRONTAB(5)
Pages that refer to this page: cronnext(1), anacron(8), cron(8)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|