OpenBSD-4.6/usr.sbin/cron/crontab.1

.\"/* Copyright 1988,1990,1993 by Paul Vixie
.\" * All rights reserved
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.\" Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
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.\" $OpenBSD: crontab.1,v 1.26 2009/02/08 17:15:11 jmc Exp $
.\"
.Dd $Mdocdate: February 8 2009 $
.Dt CRONTAB 1
.Os
.Sh NAME
.Nm crontab
.Nd maintain crontab files for individual users
.Sh SYNOPSIS
.Nm crontab
.Op Fl u Ar user
.Ar file
.Nm crontab
.Oo
.Fl e | l | r
.Oc
.Op Fl u Ar user
.Sh DESCRIPTION
.Nm
is the program used to install, deinstall, or list the tables
used to drive the
.Xr cron 8
daemon.
Each user can have their own
.Xr crontab 5 ,
and though these are files in
.Pa /var/cron/tabs ,
they are not intended to be edited directly.
.Pp
The first form of this command is used to install a new crontab from some
named file, or standard input if the pseudo-filename
.Sq Fl
is given.
.Pp
If the
.Pa /var/cron/cron.allow
file exists, then you must be listed therein in order to use
.Nm crontab .
If the
.Pa /var/cron/cron.allow
file does not exist but the
.Pa /var/cron/cron.deny
file does exist, then you must
.Em not
be listed in the
.Pa /var/cron/cron.deny
file in order to use
.Nm crontab .
If neither of these files exists then only the super user
will be allowed to use
.Nm crontab .
.Em NOTE :
if they exist,
.Pa /var/cron/cron.allow
and
.Pa /var/cron/cron.deny
must be readable by group crontab.
If
.Nm
is unable to read the files, users will not be allowed to use
.Nm crontab .
.Pp
The options are as follows:
.Bl -tag -width "-u userX"
.It Fl e
Edit the current crontab using the editor specified by
the
.Ev VISUAL
or
.Ev EDITOR
environment variables.
After you exit from the editor, the modified
.Xr crontab 5
will be installed automatically.
.It Fl l
Causes the current crontab to be displayed on standard output.
.It Fl r
Causes the current crontab to be removed.
.It Fl u Ar user
Specifies the name of the user whose
.Xr crontab 5
is to be edited.
If this option is not given,
.Nm
examines
.Dq your
.Xr crontab 5 ;
i.e., the
crontab of the person executing the command.
Note that
.Xr su 1
can confuse
.Nm
and that if you are running inside of
.Xr su 1
you should always use the
.Fl u
option for safety's sake.
.El
.Sh FILES
.Bl -tag -width "/var/cron/cron.allow" -compact
.It Pa /var/cron/cron.allow
list of users allowed to use crontab
.It Pa /var/cron/cron.deny
list of users prohibited from using crontab
.It Pa /var/cron/tabs
directory of individual crontabs
.El
.Sh DIAGNOSTICS
A fairly informative usage message appears if you run it with a bad command
line.
.Sh SEE ALSO
.Xr at 1 ,
.Xr crontab 5 ,
.Xr cron 8
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification.
.Pp
The flag
.Op Fl u
is an extension to that specification.
.Sh AUTHORS
.An Paul Vixie Aq vixie@isc.org