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ANACRON(8)		     Anacron Users' Manual		    ANACRON(8)

       anacron - runs commands periodically

       anacron [-s] [-f] [-n] [-d] [-q] [-t anacrontab] [-S spooldir] [job]
       anacron [-S spooldir] -u [-t anacrontab] [job]
       anacron [-V|-h]
       anacron -T [-t anacrontab]

       Anacron	is  used  to  execute  commands periodically, with a frequency
       specified in days.  Unlike cron(8), it does not assume that the machine
       is running continuously.	 Hence, it can be used on machines that aren't
       running 24 hours a day, to control regular jobs as daily,  weekly,  and
       monthly jobs.

       Anacron reads a list of jobs from a configuration file, /etc/anacrontab
       (see anacrontab(5)).  This file contains the list of jobs that  Anacron
       controls.   Each	 job entry specifies a period in days, a delay in min‐
       utes, a unique job identifier, and a shell command.

       For each job, Anacron checks whether this job has been executed in  the
       last  n	days,  where  n is the period specified for that job.  If not,
       Anacron runs the job's shell command, after waiting for the  number  of
       minutes specified as the delay parameter.

       After  the  command  exits, Anacron records the date in a special time‐
       stamp file for that job, so it can know when to execute it again.  Only
       the date is used for the time calculations.  The hour is not used.

       When there are no more jobs to be run, Anacron exits.

       Anacron	only  considers	 jobs  whose  identifier,  as specified in the
       anacrontab matches any of the  job  command-line	 arguments.   The  job
       arguments  can be shell wildcard patterns (be sure to protect them from
       your shell with adequate quoting).  Specifying  no  job	arguments,  is
       equivalent to specifying "*"  (That is, all jobs will be considered).

       Unless  the  -d option is given (see below), Anacron forks to the back‐
       ground when it starts, and the parent process exits immediately.

       Unless the -s or -n options are given, Anacron starts jobs  immediately
       when  their  delay  is  over.   The execution of different jobs is com‐
       pletely independent.

       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. If the LOGNAME environment variable is set, it
       will be used as From: field.

       Informative messages about what Anacron is doing are sent to syslogd(8)
       or  rsyslogd(8)	under  facility cron, priority notice.	Error messages
       are sent at priority error.

       "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 exe‐
       cuted by Anacron), are "locked", so that other copies of Anacron	 won't
       run them at the same time.

       -f     Force execution of the jobs, ignoring the timestamps.

       -u     Only update the timestamps of the jobs, to the current date, but
	      don't run anything.

       -s     Serialize execution of jobs.  Anacron will not start a  new  job
	      before the previous one finished.

       -n     Run   jobs   now.	   Ignore  the	delay  specifications  in  the
	      /etc/anacrontab file.  This options implies -s.

       -d     Don't fork to the background.  In this mode, Anacron will output
	      informational  messages to standard error, as well as to syslog.
	      The output of jobs is mailed as usual.

       -q     Suppress messages to standard error.  Only applicable with -d.

       -t some_anacrontab
	      Use specified anacrontab, rather than the default

       -T     Anacrontab testing. The configuration file will  be  tested  for
	      validity.	 If  there  is	an error in the file, an error will be
	      shown and anacron will return 1. Valid anacrontabs  will	return

       -S spooldir
	      Use  the	specified spooldir to store timestamps in. This option
	      is required for users who wish to run anacron themselves.

       -V     Print version information, and exit.

       -h     Print short usage message, and exit.

       After receiving a SIGUSR1 signal, Anacron waits for  running  jobs,  if
       any,  to	 finish	 and  then  exits.   This  can be used to stop Anacron

       Make sure that  the  time-zone  is  set	correctly  before  Anacron  is
       started.	  (The	time-zone  affects  the date).	This is usually accom‐
       plished by setting the TZ environment  variable,	 or  by	 installing  a
       /usr/lib/zoneinfo/localtime file.  See tzset(3) for more information.

       Timestamp  files	 are  created  in  the spool directory for each job in
       anacrontab. These are  never  removed  automatically  by	 anacron,  and
       should be removed by hand if a job is no longer being scheduled.

	      Contains	specifications	of jobs.  See anacrontab(5) for a com‐
	      plete description.

	      This directory is used by Anacron for storing timestamp files.


       The Anacron README file.

       Anacron never removes timestamp files.  Remove unused files manually.

       Anacron uses up to two file descriptors for each active	job.   It  may
       run out of descriptors if there are more than about 125 active jobs (on
       normal kernels).

       Mail comments, suggestions and  bug  reports  to	 Sean  'Shaleh'	 Perry

       Anacron	was  originally conceived and implemented by Christian Schwarz

       The  current  implementation  is	 a  complete  rewrite  by  Itai	  Tzur

       The    code    base    was    maintained	  by   Sean   'Shaleh'	 Perry

       Since 2004, it is maintained by Pascal  Hakim  <pasc@(|redel‐>.

       For  Fedora  is	anacron maintained by Marcela Mašláňová <mmaslano@red‐>.

Marcela Mašláňová		  2009-07-17			    ANACRON(8)

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