crontab(1)                                             crontab(1)



     NAME
          crontab - user crontab utility

     SYNOPSIS
          crontab [file]
          crontab -l
          crontab -r

     DESCRIPTION
          crontab is a utility which aids in the use of the cron
          process scheduling program.  A crontab file stipulates the
          timetable for regular process scheduling.  crontab copies
          the specified file, or standard input if no file is
          specified, into a directory that holds all users' crontabs.
          The -r flag option removes a user's crontab from the crontab
          directory.  crontab -l will list the crontab file for the
          invoking user.

          You are permitted to use crontab if your name appears in the
          file /usr/lib/cron/cron.allow.  If that file does not exist,
          the file /usr/lib/cron/cron.deny is checked to determine if
          you should be denied access to crontab.  If neither file
          exists, only root is allowed to submit a job.  The
          allow/deny files consist of one user name per line.

          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 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).  If both are
          specified as a list of elements, both are adhered to.  For
          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).  Thus, a secondary meaning of asterisk is `use the
          other field'.

          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



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     crontab(1)                                             crontab(1)



          to a newline character.  Only the first line (up to a % or
          end-of-line) of the command field is executed by the shell.
          The other strings following the percent character are made
          available to the command as standard input.  cron reads only
          one line at a time.  For example,
               0 0 * * 1 cat %GO%HOME%EARLY%
          would mail
               GO HOME EARLY
          at the requested time.

          The shell is invoked from your $HOME directory with an arg0
          of sh.  Users who desire to have their .profile executed
          must do so explicitly in the crontab file.  cron supplies a
          default environment for every shell, defining HOME, LOGNAME,
          SHELL(=/bin/sh), and PATH(=:/bin:/usr/bin:/usr/lbin). Users
          should remember to redirect the standard output and standard
          error of their commands!  If this is not done, any generated
          output or errors will be mailed to the user (via mail(1)).

     FILES
          /usr/bin/crontab
          /usr/lib/crontab
          /usr/lib/cron
          /usr/spool/cron/crontabs
          /usr/lib/cron/log
          /usr/lib/cron/cron.allow
          /usr/lib/cron/cron.deny

     SEE ALSO
          sh(1), cron(1M).

























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