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cron(1M)		System Administration Commands		      cron(1M)

       cron - clock daemon


       cron  starts  a	process	 that executes commands	at specified dates and

       You can specify regularly scheduled commands to cron according  to  in-
       structions    found    in    crontab    files	in    the    directory
       /var/spool/cron/crontabs. Users can submit their	own crontab file using
       the crontab(1) command. Commands	which are to be	executed only once can
       be submitted using the at(1) command.

       cron only examines crontab or at	command	files during its  own  process
       initialization  phase  and  when	the crontab or at command is run. This
       reduces the overhead of checking	for new	or changed files at  regularly
       scheduled intervals.

       As cron never exits, it should be executed only once. This is done rou-
       tinely  by  way	of  the	 svc:/system/cron:default  service.  The  file
       /etc/cron.d/FIFO	 file  is used as a lock file to prevent the execution
       of more than one	instance of cron.

       cron captures the output	of the job's stdout and	stderr	streams,  and,
       if  it  is not empty, mails the output to the user. If the job does not
       produce output, no mail is sent to the user. An exception is if the job
       is  an  at(1) job and the -m option was specified when the job was sub-

       cron and	at jobs	are not	executed if your account is locked.  Jobs  and
       processses  execute.  The shadow(4) file	defines	which accounts are not
       locked and will have their jobs and processes executed.

   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/de-

       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.

   Setting cron	Defaults
       To keep a log of	all actions taken by  cron,  you  must	specify	 CRON-
       LOG=YES	in  the	 /etc/default/cron file. If you	specify	CRONLOG=NO, no
       logging is done.	Keeping	the log	is a user  configurable	 option	 since
       cron usually creates huge log files.

       You  can	specify	the PATH for user cron jobs by using PATH= in /etc/de-
       fault/cron. You can set the PATH	for root cron jobs  using  SUPATH=  in
       /etc/default/cron. Carefully consider the security implications of set-
       ting PATH and SUPATH.

       Example /etc/default/cron file:


       This example enables logging and	sets the default PATH used by non-root
       jobs    to    /usr/bin:/usr/ucb:.    Root    jobs   continue   to   use

       The cron	log file is periodically rotated by logadm(1M).

       /etc/cron.d		       Main cron directory

       /etc/cron.d/FIFO		       Lock file

       /etc/default/cron	       cron default settings file

       /var/cron/log		       cron history information

       /var/spool/cron		       Spool area

       /etc/cron.d/queuedefs	       Queue description file for  at,	batch,
				       and cron

       /etc/logadm.conf		       Configuration file for logadm

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

       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       |Availability		     |SUNWcsu			   |

       svcs(1),	   at(1),    crontab(1),    sh(1),   logadm(1M),   svcadm(1M),
       queuedefs(4), shadow(4),	attributes(5), smf(5)

       The cron	service	is managed by the service management facility, smf(5),
       under the service identifier:


       Administrative actions on this service, such as enabling, disabling, or
       requesting restart, can be performed using  svcadm(1M).	The  service's
       status can be queried using the svcs(1) command.

       A  history  of all actions taken	by cron	is stored in /var/cron/log and
       possibly	in /var/cron/olog.

SunOS 5.10			  5 Aug	2004			      cron(1M)


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