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.\" $NetBSD: cron.8,v 1.5 2004/03/20 09:18:03 jdolecek Exp $
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1997-03-13 09:19:07 +03:00
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.\"
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1994-01-05 23:40:12 +03:00
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.\"/* Copyright 1988,1990,1993 by Paul Vixie
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.\" * All rights reserved
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.\" *
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.\" * Distribute freely, except: don't remove my name from the source or
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.\" * documentation (don't take credit for my work), mark your changes (don't
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.\" * get me blamed for your possible bugs), don't alter or remove this
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.\" * notice. May be sold if buildable source is provided to buyer. No
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.\" * warrantee of any kind, express or implied, is included with this
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.\" * software; use at your own risk, responsibility for damages (if any) to
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.\" * anyone resulting from the use of this software rests entirely with the
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.\" * user.
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.\" *
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.\" * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
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.\" * I'll try to keep a version up to date. I can be reached as follows:
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.\" * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul
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.\" */
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2002-01-19 06:08:50 +03:00
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.\"
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1997-03-13 09:19:07 +03:00
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.\" Id: cron.8,v 2.2 1993/12/28 08:34:43 vixie Exp
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.\"
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2004-03-20 12:18:03 +03:00
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.Dd March 20, 2004
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.Dt CRON 8
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.Sh NAME
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.Nm cron
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.Nd daemon to execute scheduled commands (Vixie Cron)
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.Sh SYNOPSIS
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.Nm
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.Sh DESCRIPTION
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.Nm
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1994-01-05 23:40:12 +03:00
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should be started from /etc/rc or /etc/rc.local. It will return immediately,
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2002-02-08 04:36:18 +03:00
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so you don't need to start it with '\*[Am]'.
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.Pp
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.Nm
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1994-01-05 23:40:12 +03:00
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searches /var/cron/tabs for crontab files which are named after accounts in
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/etc/passwd; crontabs found are loaded into memory.
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.Nm
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1994-01-05 23:40:12 +03:00
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also searches for /etc/crontab which is in a different format (see
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2004-03-20 12:18:03 +03:00
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.Xr crontab 5 ).
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.Nm
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1994-01-05 23:40:12 +03:00
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then wakes up every minute, examining all stored crontabs, checking each
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command to see if it should be run in the current minute. When executing
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commands, any output is mailed to the owner of the crontab (or to the user
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named in the MAILTO environment variable in the crontab, if such exists).
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.Pp
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1994-01-05 23:40:12 +03:00
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Additionally,
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.Nm
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1994-01-05 23:40:12 +03:00
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checks each minute to see if its spool directory's modtime (or the modtime
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on
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2004-03-20 12:18:03 +03:00
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.Pa /etc/crontab )
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1994-01-05 23:40:12 +03:00
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has changed, and if it has,
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2004-03-20 12:18:03 +03:00
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.Nm
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1994-01-05 23:40:12 +03:00
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will then examine the modtime on all crontabs and reload those which have
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changed. Thus
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2004-03-20 12:18:03 +03:00
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.Nm
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1994-01-05 23:40:12 +03:00
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need not be restarted whenever a crontab file is modified. Note that the
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2004-03-20 12:18:03 +03:00
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.Xr crontab 1
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1994-01-05 23:40:12 +03:00
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command updates the modtime of the spool directory whenever it changes a
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crontab.
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.Sh SEE ALSO
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.Xr crontab 1 ,
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.Xr crontab 5
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.Sh AUTHOR
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.An Paul Vixie
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.Aq paul@vix.com
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