64 lines
2.2 KiB
Groff
64 lines
2.2 KiB
Groff
.\" $NetBSD: cron.8,v 1.3 2002/01/19 03:08:50 wiz Exp $
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.\"
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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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.\"
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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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.TH CRON 8 "20 December 1993"
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.UC 4
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.SH NAME
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cron \- daemon to execute scheduled commands (Vixie Cron)
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.SH SYNOPSIS
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cron
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.SH DESCRIPTION
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.I Cron
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should be started from /etc/rc or /etc/rc.local. It will return immediately,
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so you don't need to start it with '&'.
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.PP
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.I Cron
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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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.I Cron
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also searches for /etc/crontab which is in a different format (see
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.IR crontab(5)).
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.I Cron
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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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Additionally,
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.I cron
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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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.IR /etc/crontab)
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has changed, and if it has,
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.I cron
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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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.I cron
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need not be restarted whenever a crontab file is modified. Note that the
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.IR crontab (1)
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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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crontab(1), crontab(5)
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.SH AUTHOR
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.nf
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Paul Vixie <paul@vix.com>
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