anacron [-s] [-f] [-n] [-d] [-q] [-t anacrontab] [-S spooldir] [job] …
anacron [-S spooldir] -u [-t anacrontab] [job] …
anacron -T [-t anacrontab]
Execute commands periodically, with a frequency specified in days. does not assume that the system is running continuously.
That is, commands missed when system is not running will be run next time system is up!
Reads a list of jobs from
/etc/anacrontab (see anacrontab(5)).
Each job entry specifies a period in days, a delay in minutes, a unique job identifier, and a shell command.
If this job has not executed in the last
n days, it is started after waiting for
After the command exits, records the date.
Only considers jobs whose identifier, matches any of the job command-line arguments which can be shell wildcard patterns (be sure to protect them from your shell with adequate quoting).
With no job arguments all jobs will be considered.
starts jobs when delay is over. The execution of jobs is independent, unless
-n are given,
If a job generates any output on its standard output or standard error, the output is mailed to the user running Anacron (usually root), or to the address contained by the MAILTO environment variable in the crontab, if such exists.
Notices are sent to syslogd) with facility
"Active" jobs (i.e. jobs that Anacron already decided to run and now wait for their delay to pass, and jobs that are currently being executed by Anacron), are "locked", so that other copies of Anacron won't run them at the same time.
SIGUSR1. Waits for running jobs, to finish and exits.
time-zone must be set correctly by setting
$TZ , or by installing a
Timestamp files created in the spool directory for each job are not removed.
/etc/anacrontabContains specifications of jobs.
# These replace cron's entries
1 5 cron.daily run-parts --report /etc/cron.daily
7 10 cron.weekly run-parts --report /etc/cron.weekly
@monthly 15 cron.monthly run-parts --report /etc/cron.monthly
/var/spool/anacrondefault directory for storing timestamp files .
period delay job-identifier command
@monthly delay job-identify command
period is specified in days, the
delay in minutes.
job-identifier can contain any non-blank character, except slashes to
identify the job in Anacron messages, and as the name for the job's timestamp file.
command can be any shell command.
Fields are separated by blank spaces or tabs.
period_name can only be set to
monthly at the present time. ensures jobs are only run once a
month, no matter the number of days in this month, or the previous month.
VAR = VALUE
VAR are removed.
No spaces around VALUE are allowed (unless they are to be part of the value).
The assignment takes effect from the next line to the end of the file, or to the next assignment of the same variable. Comment lines begin with
# and blank lines are permitted.
Continuation lines end with a
cat /etc/anacrontab SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin HOME=/root LOGNAME=root # These replace cron's entries 1 5 cron.daily run-parts --report /etc/cron.daily 7 10 cron.weekly run-parts --report /etc/cron.weekly @monthly 15 cron.monthly run-parts --report /etc/cron.monthly /etc/cron.d: -rw-r--r-- 285 May 29 2017 anacron -rw-r--r-- 822 Jun 22 15:40 atsar /etc/cron.daily: -rwxr-xr-x 311 May 29 2017 0anacron -rwxr-xr-x 1474 Sep 13 2017 apt-compat -rwxr-xr-x 314 Apr 18 2017 aptitude -rwxr-xr-x 355 Oct 25 2016 bsdmainutils -rwxr-xr-x 1597 Feb 22 2017 dpkg -rwxr-xr-x 2211 Apr 13 2014 locate -rwxr-xr-x 89 May 5 2015 logrotate -rwxr-xr-x 1065 Dec 13 2016 man-db -rwxr-xr-x 1386 Feb 15 2018 ntp -rwxr-xr-x 249 May 17 2017 passwd /etc/cron.hourly: -rwxr-xr-x 191 Feb 22 2012 fake-hwclock /etc/cron.monthly: -rwxr-xr-x 313 May 29 2017 0anacron /etc/cron.weekly: -rwxr-xr-x 312 May 29 2017 0anacron -rwxr-xr-x 723 Dec 13 2016 man-db :