crontab(1)																crontab(1)

NAME

       crontab - user crontab file

SYNOPSIS

       crontab [filename]

       crontab [-elr username]

       The  crontab utility manages a user's access with cron (see cron(1M)) by copying, creating, 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.

       If crontab is invoked with filename, this overwrites an existing crontab entry for the user that invokes it.

   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.

	 o  if	BSM audit is enabled, the user's shell is not audited and the user is not the crontab owner. This can occur if the user logs in by
	    way of a program, such as some versions of SSH, which does not set audit parameters.

       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 can 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). Time specified here is interpreted in the timezone  of  the
       cron(1M)  daemon, which is set system-wide in /etc/default/init. Entries do not use the invoking user's timezone. The specification of days
       can 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 .

       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 command field is executed by the shell. Other lines are made available to the com-
       mand as standard input. Any blank line or line beginning with a `#' is a comment and is 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 are mailed to you.

   Setting cron Jobs Across Timezones
       The  timezone  of  the  cron  daemon  sets the system-wide timezone for cron entries. This, in turn, is by set by default system-wide using
       /etc/default/init.

       If some form of daylight savings or summer/winter time is in effect, then jobs scheduled during the switchover  period  could  be  executed
       once, twice, or not at all.

       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 com-
		plete, 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 can only be done by a user with the solaris.jobs.admin authorization. The envi-
		ronment variable EDITOR determines which editor is invoked with the -e option. The default  editor  is	ed(1).	All  crontab  jobs
		should	be  submitted  using  crontab. Do not add jobs by just editing the crontab file, because cron is not aware of changes made
		this way.

		If all lines in the crontab file are deleted, the old crontab file is restored. The correct way to delete all lines is	to  remove
		the crontab file using the -r option.

       -l	Lists the crontab file for the invoking user. Only a user with the solaris.jobs.admin authorization can specify a username follow-
		ing 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 directory.

       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.

       See environ(5) for descriptions of the following environment variables that affect  the	execution  of  crontab:  LANG,	LC_ALL,  LC_CTYPE,
       LC_MESSAGES, and NLSPATH.

       EDITOR	       Determine the editor to be invoked when the -e option is specified. This is overriden by the VISUAL environmental variable.
		       The default editor is ed(1).

       VISUAL	       Determine the visual editor to be invoked when the -e option is specified. If VISUAL is not specified, then the environment
		       variable EDITOR is used. If that is not set, the default is ed(1).

       The following exit values are returned:

       0	Successful completion.

       >0	An error occurred.

       /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 attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

       atq(1), atrm(1), auths(1), ed(1), sh(1), vi(1), cron(1M), su(1M), auth_attr(4), attributes(5), environ(5), standards(5)

       If  you	inadvertently  enter  the crontab command with no arguments, 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 can be unpredictable. Instead, the super-user  should  first
       use su(1M) to become super-user to the other user's login before making any changes to the crontab file.

       When  updating  cron,  check  first for existing crontab entries that can be scheduled close to the time of the update. Such entries can be
       lost if the update process completes after the scheduled event. This can happen because, when cron is notified by  crontab  to  update  the
       internal  view  of  a user's crontab file, it first removes the user's existing internal crontab and any internal scheduled events. Then it
       reads the new crontab file and rebuilds the internal crontab and events. This last step takes time, especially with a large  crontab  file,
       and  can  complete  after an existing crontab entry is scheduled to run if it is scheduled too close to the update. To be safe, start a new
       job at least 60 seconds after the current date and time.

								    10 Aug 2005 							crontab(1)