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CRON(8)                     System Manager's Manual                    CRON(8)

       cron - clock daemon


       Cron  executes  commands  at specified dates and times according to the
       instructions in the file /usr/lib/crontab.  Since cron never exits,  it
       should  only  be executed once.  This is best done by running cron from
       the initialization process through the file /etc/rc; see init(8).

       Crontab consists of lines of six fields each.  The fields are separated
       by  spaces or tabs.  The first five are integer patterns to specify the
       minute (0-59), hour (0-23), day of the month (1-31), month of the  year
       (1-12),  and  day  of the week (1-7 with 1=Monday).  Each of these pat-
       terns may contain a number in the range above; two numbers separated by
       a  minus meaning a range inclusive; a list of numbers separated by com-
       mas meaning any of the numbers; or an asterisk meaning all  legal  val-
       ues.   The sixth field is a string that is executed by the Shell at the
       specified times.  A percent character in this field is translated to  a
       new-line  character.  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.

       Crontab is examined by cron every minute.


                                4 February 1983                        CRON(8)