CRONTAB(1) BSD General Commands Manual CRONTAB(1)NAMEcrontab — maintain crontab files for individual users (V3)
SYNOPSIScrontab [-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 nei‐
ther of these files exists, then depending on site-dependent configura‐
tion 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 com‐
mand line.
SEE ALSOcrontab(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⟩
BSD December 29, 1993 BSD
