cron/dist/crontab.1

.\"	$NetBSD: crontab.1,v 1.3 2010/05/07 20:43:40 christos Exp $
.\"
.\"/* Copyright 1988,1990,1993 by Paul Vixie
.\" * All rights reserved
.\" */
.\"
.\" Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
.\"
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.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
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.\" Id: crontab.1,v 1.7 2004/01/23 19:03:32 vixie Exp
.\"
.Dd May 6, 2010
.Dt CRONTAB 1
.Os
.Sh NAME
.Nm crontab
.Nd maintain crontab files for individual users (ISC Cron V4.1)
.Sh SYNOPSIS
.Nm
.Op Fl u Ar user
.Nm
.Op Fl l
.Op Fl r
.Op Fl e
.Sh DESCRIPTION
.Nm
is the program used to install, deinstall or list the tables
used to drive the
.Xr cron 8
daemon in ISC Cron.
Each user can have their own crontab, and though
these are files in
.Pa /var/cron ,
they are not intended to be edited directly.
.Pp
If the
.Pa /var/cron/allow
file exists, then you must be listed therein in order to be allowed to use
this command.
If the
.Pa /var/cron/allow
file does not exist but the
.Pa /var/cron/deny
file does exist, then you must not be listed in the
.Pa /var/cron/deny
file in order to use this command.
If neither of these files exists, depending on the compiled in settings,
only the super user will be allowed to use this command,
or everyone will be allowed to use this command.
On
.Nx
everyone is allowed to use this command.
.Pp
The default maximum size for a crontab is 256 kilobytes, but this may be
changed for all users on the system by putting the desired maximum size
(in bytes) in the
.Pa /var/cron/maxtabsize
file.
.Pp
If the
.Fl u
option is given, it specifies the name of the user whose crontab is to be
tweaked.  If this option is not given,
.Nm
examines
.Dq your
crontab, 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.
.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
.Dq -
is given.
.Pp
The
.Fl l
option causes the current crontab to be displayed on standard output.
.Pp
The
.Fl r
option causes the current crontab to be removed.
.Pp
The
.Fl e
option is used to edit the current crontab using the editor specified by
the
.Dv VISUAL
or
.Dv EDITOR
environment variables.
After you exit from the editor, the modified crontab will be installed
automatically.
.Sh SEE ALSO
.Xr crontab 5 ,
.Xr cron 8
.Sh FILES
.Bl -tag -width /var/cron/maxtabsize -compact
.It Pa /var/cron/allow
Optional list of users that are allowed to use
.Nm .
.It Pa /var/cron/deny
Optional list of users that are disallowed to use
.Nm .
.It Pa /var/cron/maxtabsize
Maximum size of
.Nm
.It Pa /var/cron/tabs/
Directory containing the individual user crontab files, named after the user.
files.
Defaults to
.Dv 256
kilobytes.
.El
.Sh STANDARDS
The
.Nm
command conforms to
.St -p1003.2 .
This new command syntax
differs from previous versions of Vixie Cron, as well as from the classic
.At V3
syntax.
.Sh DIAGNOSTICS
A fairly informative usage message appears if you run it with a bad command
line.
.Sh AUTHORS
.An Paul Vixie
.Aq vixie@isc.org