crontab(1) User Commands crontab(1)
NAME
crontab - user crontab file
SYNOPSIS
crontab [ filename ]
crontab -e [username]
crontab -r [username]
crontab -l [username]
AVAILABILITY
SUNWcsu
DESCRIPTION
crontab manages a user's access with cron by copying, creat-
ing, listing, and removing crontab files. If invoked
without options, crontab copies the specified file, or the
standard input if no file is specified, into a directory
that holds all users' crontabs.
crontab Access Control
Users: Access to crontab is allowed:
+o if the user's name appears in
/etc/cron.d/cron.allow.
+o if /etc/cron.d/cron.allow does not exist and the
user's name is not in /etc/cron.d/cron.deny.
Users: Access to crontab is denied:
+o if /etc/cron.d/cron.allow exists and the user's name
is not in it.
+o if /etc/cron.d/cron.allow does not exist and user's
name is in /etc/cron.d/cron.deny.
+o if neither file exists.
Note: The rules for allow and deny apply to root only if the
allow/deny files exist.
The allow/deny files consist of one user name per line.
crontab Entry Format
A crontab file consists of lines of six fields each. The
fields are separated by spaces or tabs. The first five are
integer patterns that specify the following:
minute (0-59),
hour (0-23),
day of the month (1-31),
month of the year (1-12),
day of the week (0-6 with 0=Sunday).
Each of these patterns may be either an asterisk (meaning
all legal values) or a list of elements separated by commas.
An element is either a number or two numbers separated by a
minus sign (meaning an inclusive range). Note that the
specification of days may be made by two fields (day of the
month and day of the week). If both are specified as a list
of elements, both are adhered to. For example, 0 0 1,15 * 1
would run a command on the first and fifteenth of each
month, as well as on every Monday. To specify days by only
one field, the other field should be set to * (for example,
0 0 * * 1 would run a command only on Mondays).
The sixth field of a line in a crontab file is a string that
is executed by the shell at the specified times. A percent
character in this field (unless escaped by \) is translated
to a new-line character. Only the first line (up to a % or
end of line) of the command field is executed by the shell.
Other lines are made available to the command as standard
input. Any line beginning with a # is a comment and will be
ignored.
The shell is invoked from your $HOME directory with an arg0
of sh. Users who desire to have their .profile executed
must explicitly do so in the crontab file. cron supplies a
default environment for every shell, defining HOME, LOGNAME,
SHELL(=/bin/sh), TZ, and PATH. The default PATH for user
cron jobs is /usr/bin; while root cron jobs default to
/usr/sbin:/usr/bin. The default PATH can be set in
/etc/default/cron. (See cron(1M)).
If you do not redirect the standard output and standard
error of your commands, any generated output or errors will
be mailed to you.
OPTIONS
-e edits a copy of the current user's crontab file,
or creates an empty file to edit if crontab does
not exist. When editing is complete, the file is
installed as the user's crontab file. If a user-
name is given, the specified user's crontab file
is edited, rather than the current user's crontab
file; this may only be done by a privileged user.
The environment variable EDITOR determines which
editor is invoked with the -e option. The default
editor is ed(1).
Note: All crontab jobs should be submitted using
crontab; you should not add jobs by just editing
crontab file because cron will not be aware of
changes made this way.
-l lists the crontab file for the invoking user.
Only a privileged user can specify a username fol-
lowing the -r or -l options to remove or list the
crontab file of the specified user.
-r removes a user's crontab from the crontab direc-
tory.
FILES
/etc/cron.d main cron directory
/etc/cron.d/cron.allow list of allowed users
/etc/default/cron contains cron default settings
/etc/cron.d/cron.deny list of denied users
/var/cron/log accounting information
/var/spool/cron/crontabs spool area for crontab.
SEE ALSO
atq(1), atrm(1), ed(1), sh(1), cron(1M), su(1M)
NOTES
If you inadvertently enter the crontab command with no
argument(s), do not attempt to get out with a CTRL-D. This
removes all entries in your crontab file. Instead, exit
with a CTRL-C.
If a privileged user modifies another user's crontab file,
resulting behavior may be unpredictable. Instead, the
privileged user should first su(1M) to the other user's
login before making any changes to the crontab file.
SunOS 5.4 Last change: 2 Mar 1994