CRONTAB(1)                           SysV                           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.

     You can use crontab if your name appears in the file
     /usr/lib/cron/cron.allow. If that file does not crontab checks the file
     /usr/lib/cron/cron.deny to determine if you should be allowed access.  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 contain 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 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 is mailed to you.

OPTIONS
     -r        Removes your crontab from the crontab directory.

     -l        Lists the crontab file for the invoking user.

WARNING

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

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 Managing Your SysV System Software.