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



NAME
       anacron - runs commands periodically

SYNOPSIS
       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]

DESCRIPTION
       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 con-
       tains the list of jobs that Anacron controls.  Each job entry specifies a period in days, a delay in minutes, 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 spec-
       ified 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 timestamp 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 background when it starts, and the parent pro-
       cess 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 completely independent.

       If  a  job generates any output on its standard output or standard error, the output is mailed to the user run-
       ning 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 executed by Anacron), are "locked", so that other copies of Anacron won't run them at
       the same time.

OPTIONS
       -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 0.

       -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.

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

NOTES
       Make sure that the time-zone is set correctly before Anacron is started.  (The  time-zone  affects  the  date).
       This  is  usually  accomplished  by  setting  the  TZ  environment  variable, or by installing a /usr/lib/zone-
       info/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 automat-
       ically by anacron, and should be removed by hand if a job is no longer being scheduled.

FILES
       /etc/anacrontab
              Contains specifications of jobs.  See anacrontab(5) for a complete description.

       /var/spool/anacron
              This directory is used by Anacron for storing timestamp files.

SEE ALSO
       anacrontab(5),cron(8),tzset(3)

       The Anacron README file.

BUGS
       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 <shaleh@(debian.org|valinux.com)>.

AUTHOR
       Anacron was originally conceived and implemented by Christian Schwarz <schwarzATmonet.de>.

       The current implementation is a complete rewrite by Itai Tzur <itzurATactcom.il>.

       The code base was maintained by Sean 'Shaleh' Perry <shaleh@(debian.org|valinux.com)>.

       Since 2004, it is maintained by Pascal Hakim <pasc@(debian.org|redellipse.net)>.

       For Fedora is anacron maintained by Marcela Maslanova <mmaslanoATredhat.com>.



Marcela Maslanova                 2009-07-17                        ANACRON(8)