ANACRONTAB(5)

๐Ÿ’… ANACRONTAB(5) โ€” /etc/anacrontab, from File Formats, bestie ๐Ÿ’…

๐ŸŒธ NAME ๐ŸŒธ

Bestie, /etc/anacrontab is literally the configuration file for Anacron. It describes the jobs controlled by anacron(8). It can contain three types of lines: job-description lines, environment assignments, or empty lines. periodt โœจ

โœจ DESCRIPTION โœจ

okay so job-description lines can have this exact 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. ๐Ÿ—“๏ธ
  • 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. โณ
  • The job-identifier variable specifies a unique name of a job which is used in the log files. ๐Ÿท๏ธ
  • 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. ๐Ÿ’ป

Environment assignment lines can have this exact 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. iykyk ๐Ÿซถ

  • START_HOURS_RANGE 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. โšก
  • RANDOM_DELAY 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. ๐ŸŽฒ
  • If MAILTO is defined (and non-empty), mail is sent to the specified address, otherwise, system user is used. ๐Ÿ“ฌ
  • If MAILFROM is defined (and non-empty), it is used as the envelope sender address, otherwise, system user is used. ๐Ÿ“ฎ
  • If NO_MAIL_OUTPUT is defined (and non-empty), the standard output and error descriptors of job processes are not redirected and e-mailed. ๐Ÿ™ˆ

(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.)

Empty lines are either blank lines, line containing white spaces only, or lines with white spaces followed by a '#' followed by an arbitrary comment. ๐Ÿงš

You can continue a line onto the next line by adding a \ at the end of it. ๐Ÿ”—

๐Ÿšจ 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.

๐ŸŽ€ EXAMPLE ๐ŸŽ€

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. ๐Ÿ‘‘

# 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

๐Ÿฆ‹ SEE ALSO ๐Ÿฆ‹

๐Ÿ’œ AUTHOR ๐Ÿ’œ

Itai Tzur

Currently maintained by Pascal Hakim.

For Fedora, maintained by Marcela Maลกlรกลˆovรก. ๐ŸŒธ


๐Ÿ’– xoxo bestie โ€” source/version: cronie; date: 2012-11-22; manual: ANACRONTAB(5) ๐Ÿ’–

๐Ÿ“ฆ where this page comes from