crontab

CRONTAB(1)                   General Commands Manual                  CRONTAB(1)

NAME
     crontab – maintain crontab files for individual users (V3)

SYNOPSIS
     crontab [-u user] file
     crontab [-u user] { -l | -r | -e }

DESCRIPTION
     The crontab utility is the program used to install, deinstall or list the
     tables used to drive the cron(8) daemon in Vixie Cron.  Each user can have
     their own crontab, and they are not intended to be edited directly.

     (Darwin note: Although cron(8) and crontab(5) are officially supported
     under Darwin, their functionality has been absorbed into launchd(8), which
     provides a more flexible way of automatically executing commands.  See
     launchctl(1) for more information.)

     If the /usr/lib/cron/cron.allow file exists, then you must be listed
     therein in order to be allowed to use this command.  If the
     /usr/lib/cron/cron.allow file does not exist but the
     /usr/lib/cron/cron.deny file does exist, then you must not be listed in the
     /usr/lib/cron/cron.deny file in order to use this command.  If neither of
     these files exists, then depending on site-dependent configuration
     parameters, only the super user will be allowed to use this command, or all
     users will be able to use this command.  The format of these files is one
     username per line, with no leading or trailing whitespace.  Lines of other
     formats will be ignored, and so can be used for comments.

     The first form of this command is used to install a new crontab from some
     named file or standard input if the pseudo-filename ‘-’ is given.

     The following options are available:

     -u      Specify the name of the user whose crontab is to be tweaked.  If
             this option is not given, crontab examines “your” crontab, i.e.,
             the crontab of the person executing the command.  Note that su(1)
             can confuse crontab and that if you are running inside of su(1) you
             should always use the -u option for safety's sake.

     -l      Display the current crontab on standard output.

     -r      Remove the current crontab.

     -e      Edit the current crontab using the editor specified by the VISUAL
             or EDITOR environment variables.  The specified editor must edit
             the file in place; any editor that unlinks the file and recreates
             it cannot be used.  After you exit from the editor, the modified
             crontab will be installed automatically.

FILES
     /usr/lib/cron/cron.allow
     /usr/lib/cron/cron.deny

DIAGNOSTICS
     A fairly informative usage message appears if you run it with a bad command
     line.

SEE ALSO
     crontab(5), compat(5), cron(8), launchctl(1)

STANDARDS
     The crontab command conforms to IEEE Std 1003.2 (“POSIX.2”).  The new
     command syntax differs from previous versions of Vixie Cron, as well as
     from the classic SVR3 syntax.

AUTHORS
     Paul Vixie ⟨paul@vix.com⟩

macOS 12.1                      December 29, 1993                     macOS 12.1