xref: /freebsd/usr.sbin/cron/crontab/crontab.1 (revision 7773002178c8dbc52b44e4d705f07706409af8e4)
1.\"/* Copyright 1988,1990,1993 by Paul Vixie
2.\" * All rights reserved
3.\" *
4.\" * Distribute freely, except: don't remove my name from the source or
5.\" * documentation (don't take credit for my work), mark your changes (don't
6.\" * get me blamed for your possible bugs), don't alter or remove this
7.\" * notice.  May be sold if buildable source is provided to buyer.  No
8.\" * warrantee of any kind, express or implied, is included with this
9.\" * software; use at your own risk, responsibility for damages (if any) to
10.\" * anyone resulting from the use of this software rests entirely with the
11.\" * user.
12.\" *
13.\" * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
14.\" * I'll try to keep a version up to date.  I can be reached as follows:
15.\" * Paul Vixie          <paul@vix.com>          uunet!decwrl!vixie!paul
16.\" */
17.\"
18.\" $FreeBSD$
19.\"
20.Dd December 29, 1993
21.Dt CRONTAB 1
22.Os
23.Sh NAME
24.Nm crontab
25.Nd maintain crontab files for individual users (V3)
26.Sh SYNOPSIS
27.Nm
28.Op Fl u Ar user
29.Ar file
30.Nm
31.Op Fl u Ar user
32{
33.Fl l |
34.Fl r |
35.Fl e
36}
37.Sh DESCRIPTION
38The
39.Nm
40utility is the program used to install, deinstall or list the tables
41used to drive the
42.Xr cron 8
43daemon in Vixie Cron.  Each user can have their own crontab, and though
44these are files in
45.Pa /var ,
46they are not intended to be edited directly.
47.Pp
48If the
49.Pa allow
50file exists, then you must be listed therein in order to be allowed to use
51this command.  If the
52.Pa allow
53file does not exist but the
54.Pa deny
55file does exist, then you must
56.Em not
57be listed in the
58.Pa deny
59file in order to use this command.  If neither of these files exists, then
60depending on site-dependent configuration parameters, only the super user
61will be allowed to use this command, or all users will be able to use this
62command.
63The format of these files is one username per line,
64with no leading or trailing whitespace.
65Lines of other formats will be ignored,
66and so can be used for comments.
67.Pp
68The first form of this command is used to install a new crontab from some
69named file or standard input if the pseudo-filename ``-'' is given.
70.Pp
71The following options are available:
72.Bl -tag -width indent
73.It Fl u
74Specify the name of the user whose crontab is to be
75tweaked.  If this option is not given,
76.Nm
77examines "your" crontab, i.e., the crontab of the person executing the
78command.  Note that
79.Xr su 1
80can confuse
81.Nm
82and that if you are running inside of
83.Xr su 1
84you should always use the
85.Fl u
86option for safety's sake.
87.It Fl l
88Display the current crontab on standard output.
89.It Fl r
90Remove the current crontab.
91.It Fl e
92Edit the current crontab using the editor specified by
93the
94.Ev VISUAL
95or
96.Ev EDITOR
97environment variables.
98The specified editor
99.Em must
100edit the file in place;
101any editor that unlinks the file and recreates it cannot be used.
102After you exit
103from the editor, the modified crontab will be installed automatically.
104.El
105.Sh SEE ALSO
106.Xr crontab 5 ,
107.Xr cron 8
108.Sh FILES
109.Bl -tag -width /var/cron/allow -compact
110.It Pa /var/cron/allow
111.It Pa /var/cron/deny
112.El
113.Sh STANDARDS
114The
115.Nm
116command conforms to
117.St -p1003.2
118with the exception that the dangerous variant of calling
119.Nm
120without a file name in the first form of the command is not allowed by
121this implementation.
122The pseudo-filename ``-'' must be specified to read from standard input.
123The new command syntax
124differs from previous versions of Vixie Cron, as well as from the classic
125SVR3 syntax.
126.Sh DIAGNOSTICS
127A fairly informative usage message appears if you run it with a bad command
128line.
129.Sh AUTHORS
130.An Paul Vixie Aq paul@vix.com
131