CRONTAB(1) General Commands Manual CRONTAB(1)
crontab - install, edit, remove or list a user's crontab file
crontab [ filename ]
crontab -e [ username ]
crontab -l [ username ]
crontab -r [ username ]
crontab copies the specified file, or the standard input if no file is
specified, into a directory that holds all users' crontab files. A
user's crontab file lists commands that are to be executed on behalf of
that user at specified times on specified dates; the format of these
files is described in crontab(5).
If the file /var/spool/cron/cron.allow exists, only users whose user-
name appears in it can use crontab. If that file does not exist, how-
ever, crontab checks the /var/spool/cron/cron.deny file to determine if
the user should be denied the use of crontab. If neither file exists,
only the super-user is allowed to submit a crontab job. If cron.allow
does not exist and cron.deny exists and is empty, global usage is per-
mitted. The allow/deny files consist of one user name per line.
-e Make a copy of the current user's crontab file, or create an
empty file if it does not exist, and edit that file. The vi(1)
editor will be used unless the environment variable VISUAL or
EDITOR indicates an alternate editor. When editing is complete,
install the file as the user's crontab file if it was modified.
If a username is given, the specified user's crontab file is
edited, rather than the current user's crontab file; this may
only be done by the super-user.
-l List the user's crontab file.
-r Remove the current user's crontab file from the crontab direc-
tory. If a username is given, the specified user's crontab file
is removed, rather than the current user's crontab file; this
may only be done by the super-user.
/var/spool/cron main cron directory
/var/spool/cron/crontabs spool area
list of allowed users
list of denied users
sh(1), crontab(5), cron(8)
If you inadvertently enter the crontab command with no argument, do not
attempt to get out by typing CTRL-D. This removes all entries in your
crontab file. Instead, exit by typing your interrupt character (nor-
9 September 1987 CRONTAB(1)