CRON(8)                                                   CRON(8)

       cron - daemon to execute scheduled commands (Vixie Cron)


       Cron  should be started from /etc/rc or /etc/rc.local.  It
       will return immediately, so you don't  need  to  start  it
       with '&'.

       Cron  searches /var/spool/cron for crontab files which are
       named after accounts in /etc/passwd;  crontabs  found  are
       loaded  into  memory.  Cron also searches for /etc/crontab
       and the files in the /etc/cron.d/ directory, which are  in
       a  different  format (see crontab(5)).  Cron then wakes up
       every minute, examining all stored crontabs, checking each
       command  to see if it should be run in the current minute.
       When executing commands, any output is mailed to the owner
       of  the  crontab (or to the user named in the MAILTO envi-
       ronment variable in the crontab, if such exists).

       Additionally, cron checks each minute to see if its  spool
       directory's  modtime  (or the modtime on /etc/crontab) has
       changed, and if it has, cron will then examine the modtime
       on all crontabs and reload those which have changed.  Thus
       cron need not be restarted whenever a crontab file is mod-
       ified.   Note that the Crontab(1) command updates the mod-
       time of the spool directory whenever it changes a crontab.

       crontab(1), crontab(5)

       Paul Vixie <>

                         20 December 1993                       1