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CRONTAB(1) NetBSD General Commands Manual CRONTAB(1)
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crontab -- maintain crontab files for individual users (ISC Cron V4.1)
crontab [-u user]
crontab is the program used to install, deinstall, or list the tables
used to drive the cron(8) daemon in ISC Cron. Each user can have their
own crontab, and though these are files in /var/cron, they are not
intended to be edited directly.
If the /var/cron/allow file exists, then you must be listed therein in
order to be allowed to use this command. If the /var/cron/allow file
does not exist but the /var/cron/deny file does exist, then you must not
be listed in the /var/cron/deny file in order to use this command. If
neither of these files exists, depending on the compiled in settings,
only the super user will be allowed to use this command, or everyone will
be allowed to use this command. On NetBSD everyone is allowed to use
The default maximum size for a crontab is 256 kilobytes, but this may be
changed for all users on the system by putting the desired maximum size
(in bytes) in the /var/cron/maxtabsize file.
If the -u option is given, it specifies 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.
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 -l option causes the current crontab to be displayed on standard out-
The -r option causes the current crontab to be removed.
The -e option is used to edit the current crontab using the editor speci-
fied by the VISUAL or EDITOR environment variables. After you exit from
the editor, the modified crontab will be installed automatically.
/var/cron/allow Optional list of users that are allowed to use
/var/cron/deny Optional list of users that are disallowed to use
/var/cron/maxtabsize Maximum size of crontab files. Defaults to 256
/var/cron/tabs/ Directory containing the individual user crontab
files, named after the user.
A fairly informative usage message appears if you run it with a bad com-
The crontab command conforms to IEEE Std 1003.2 (``POSIX.2''). This new
command syntax differs from previous versions of Vixie Cron, as well as
from the classic Version 3 AT&T UNIX syntax.
Paul Vixie <firstname.lastname@example.org>
NetBSD 9.1 May 6, 2010 NetBSD 9.1