anacrontab(5) - phpMan

ANACRONTAB(5) File Formats ANACRONTAB(5)

NAME
/etc/anacrontab - configuration file for Anacron

DESCRIPTION
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 speci-
fies 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 com-
mand 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 sched-
uled 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.

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 the 0anacron cron job (which is a part of
crontab(1)) into the /etc/cron.hourly/jobs.deny directory.

EXAMPLE
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