crontab(1)
_________________________________________________________________
crontab Command
user crontab file in DG/UX
_________________________________________________________________
SYNTAX
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' crontab
entries. Crontab entries are commands a user wants cron to
execute at a specified time using a subshell. The -r option
removes a user's crontab from the crontab directory. Crontab -l
will list the crontab file for the invoking user.
A user is permitted to use crontab if their name appears in the
file /usr/lib/cron/cron.allow. If that file does not exist, the
file /usr/lib/cron/cron.deny is checked to determine if the user
should be denied access to crontab. If neither file exists, only
root is allowed to submit a job. The allow/deny files consist of
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 time at which the commands are to be
executed by cron. These are as follows:
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).
DG/UX 4.00 Page 1
Licensed material--property of copyright holder(s)
crontab(1)
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. When your crontab entry is executed, only
the first line (up to a % or end of line) of the command field is
executed by the subshell. The other lines are made available to
the command as standard input.
The subshell 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:).
NOTE: Users should remember to redirect the standard output and
standard error of their commands in the crontab file! If this is
not done, any generated output or errors will be mailed to the
user.
FILES
/usr/lib/cron main cron directory
/usr/spool/cron/crontabs spool area
/usr/lib/cron/log accounting information
/usr/lib/cron/cron.allow list of allowed users
/usr/lib/cron/cron.deny list of denied users
SEE ALSO
at(1), sh(1).
cron(1M) in the System Manager's Reference for the DG/UX System
DG/UX 4.00 Page 2
Licensed material--property of copyright holder(s)