CRONTAB(1)                                             CRONTAB(1)



     NAME
          crontab - user crontab file

     SYNOPSIS
          crontab [file]
          crontab -r
          crontab -l

     DESCRIPTION
          crontab copies the specified file, or standard input if no
          file is specified, into a directory that holds all users'
          crontabs.  The -r option removes a user's crontab from the
          crontab directory.  crontab -l will list the crontab file
          for the invoking user.

          Users are permitted to use crontab if their names appear 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 the user should be denied access to crontab. If
          neither file exists, only root is allowed to submit a job.
          If cron.allow does not exist and cron.deny exists but is
          empty, global usage is permitted.  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).

          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 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



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     CRONTAB(1)                                             CRONTAB(1)



          standard input.

          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), and PATH(=:/bin:/usr/bin:/usr/lbin).

          If you do not redirect the standard output and standard
          error of your commands, any generated output or errors will
          be mailed to you.

     FILES
          /usr/lib/cron       main cron directory
          /usr/spool/cron/crontabsspool area
          /usr/lib/cron/log   accounting information
          /usr/lib/cron/cron.allowlist of allowed users
          /usr/lib/cron/cron.denylist of denied users

     SEE ALSO
          sh(1).
          cron(1M) in the System Administrator's Reference Manual.

     WARNINGS
          If you inadvertently enter the crontab command with no
          argument(s), do not attempt to get out with a CTRL-d. This
          will cause all entries in your crontab file to be removed.
          Instead, exit with a DEL.

     ORIGIN
          AT&T V.3
























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