SunOS man pages : crontab (1)
User Commands crontab(1)
NAME
crontab - user crontab file
SYNOPSIS
crontab [ filename ]
crontab [ -elr ] username
DESCRIPTION
The crontab utility manages a user's access with cron (see
cron(1M)) by copying, creating, listing, and removing cron-
tab files. If invoked without options, crontab copies the
specified file, or the standard input if no file is speci-
fied, 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, only a user with the
solaris.jobs.user authorization is allowed to submit a
job.
Note that 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).
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User Commands crontab(1)
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). Both are adhered to if specified
as a list of elements. See EXAMPLES.
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 NEWLINE character.
Only the first line (up to a `%' or end of line) of the com-
mand field is executed by the shell. Other lines are made
available to the command as standard input. Any line begin-
ning with a `#' is a comment and will be ignored. The file
should not contain blank lines.
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
The following options are supported:
-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 username 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 user with the solaris.jobs.admin authoriza-
tion. The environment variable EDITOR determines which
editor is invoked with the -e option. The default edi-
tor is ed(1). Note that all crontab jobs should be
submitted using crontab; you should not add jobs by
just editing the crontab file because cron will not be
aware of changes made this way.
-l Lists the crontab file for the invoking user. Only a
user with the solaris.jobs.admin authorization can
specify a username following the -r or -l options to
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User Commands crontab(1)
remove or list the crontab file of the specified user.
-r Removes a user's crontab from the crontab directory.
EXAMPLES
Example 1: Cleaning up core files
This example cleans up core files every weekday morning at
3:15 am:
15 3 * * 1-5 find $HOME -name core 2>/dev/null | xargs rm -f
Example 2: Mailing a birthday greeting
0 12 14 2 * mailx john%Happy Birthday!%Time for lunch.
Example 3: Specifying days of the month and week
This 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.
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment
variables that affect the execution of crontab: LC_TYPE,
LC_MESSAGES, and NLSPATH.
EDITOR
Determine the editor to be invoked when the -e option
is specified. The default editor is ed(1). If both
the EDITOR and VISUAL environment variables are set,
the value of the VISUAL variable is selected as the
editor.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
>0 An error occurred.
FILES
/etc/cron.d
main cron directory
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User Commands crontab(1)
/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
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcsu |
|_____________________________|_____________________________|
SEE ALSO
atq(1), atrm(1), auths(1), ed(1), sh(1), cron(1M), su(1M),
auth_attr(4), attributes(5), environ(5)
NOTES
If you inadvertently enter the crontab command with no
argument(s), do not attempt to get out with <Control-d>.
This removes all entries in your crontab file. Instead, exit
with <Control-c>.
If an authorized user modifies another user's crontab file,
resulting behavior may be unpredictable. Instead, the
super-user should first su(1M) to the other user's login
before making any changes to the crontab file.
When updating a user's crontab file with the crontab com-
mand, the cron process sees this update immediately when no
cron jobs are running. However, if cron is running any cron
job(s) at the time of updating, it could take a maximum of
60 seconds before cron is aware of this update. Therefore,
to be safe, a new job should be started at least 60 seconds
after the current date and time.
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