user crontab file
crontab -e [username]
crontab -r [username]
crontab -l [username]
copies the specified file,
or standard input if no file is specified,
into a directory that holds all users' crontab files.
The following options are available:
Edits a copy of the user's
file, or creates an empty file to edit if
one does not exist.
If the editor exits with a non-zero status,
the existing crontab file is left unchanged.
When editing is complete, the file is installed as the user's
The crontab command determines which editor to invoke based on
When the POSIX2 environment variable is set,
crontab invokes the editor specified by the EDITOR
If EDITOR is null (or not set), it invokes
When POSIX2 is not set,
crontab invokes the editor specified by the
VISUAL environment variable, and if that is null, it invokes
the editor specified by
the EDITOR environment variable, and if that is null, it
Lists the user's crontab file.
Removes the user's crontab from the crontab directory.
Only a privileged user can use
username following the -e, -l, or -r
options, to edit, list, or remove the
crontab file of the specified user.
allow and deny files
Users can use
if their names appear in the file
If that file does not exist,
is checked to determine if the user
should be denied access to
If neither file exists, only root can
submit a job.
If cron.allow does not exist and cron.deny exists but is
empty, global usage is permitted.
The allow and deny files consist of one user name
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:
Each of these patterns may
be either an asterisk (meaning all valid values)
or a list of elements separated by commas.
An element is either a number or
two numbers separated by a dash
(identifying 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 runs 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 runs a command only on Mondays).
day of the month (1-31)
month of the year (1-12)
day of the week (0-6 with 0=Sunday)
The sixth field of a line in a crontab
file is a string that is executed by the shell
at the times specified.
A percent character
in this field (unless escaped by
is translated to a newline
Only the first line (up to a ``%'' or end of line) of
the command field is executed by the shell.
The other lines are made available to the
command as standard input.
Any line beginning with a ``#'' is a comment and is ignored.
The shell specified in the /etc/passwd file for your login is
used as long as its name ends in "/sh"; otherwise,
/usr/bin/sh is used.
The shell is invoked from your
directory with an
arg0 of sh.
Users who want to have their .profile executed must
explicitly do so in the crontab file.
supplies a default environment for every shell, defining
HOME, LOGNAME, SHELL(=/bin/sh),
If you do not redirect the standard output
and standard error of your commands,
any generated output or errors
is mailed to you.
list of allowed users
list of denied users
main cron directory
language-specific message file (See LANG on
If you inadvertently enter the
command with no arguments,
exit using the <Del> key.
Do not exit with a
if you do, then all entries in your
file will be removed.
If a privileged user modifies another user's crontab file, resulting
behavior may be unpredictable.
Instead, the privileged user
to the other user's login before making
changes to the crontab file.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004