Reference Manual


cron - start or stop the CRON daemon
cron on | off | d | D [crontab]


Command cron on starts the NAT32 CRON daemon. At one-minute intervals, cron opens the file crontab (or the file specified as argument crontab) in the current directory, loads it into memory and processes each entry. File crontab contains entries specifying the time and date for execution of a command. Commands can be any NAT32 command, or a command file, a URL, or a tcl script. If the current time matches an entry, the NAT32 shell is called to execute the associated command. When the command returns, the next entry in crontab is processed.

The format of crontab entries is:

time_spec command
The format of a time_spec is:
minute hour day-of-month month day-of-week

The above fields are defined as:

minute:       0-59
hour:         0-23
day-of-month: 0-31
month:        0-12 or Jan Feb Mar etc.
day-of-week:  0-7  or Sun Mon Tue etc.
A field may be an asterisk (*) to denote any.

Ranges, lists and steps are allowed:

8-11 denotes 8, 9, 10 and 11.
1,2,5,9 or 0-4,8-12
0-23/2 denotes 0 2 4 8 etc.
The remainder of the line specifies the command to be run. Any NAT32 command can be specified.
A time_spec can also have the following format:
Crontab entries starting with # are comments.
# run at 09:00 every day
0 9 * * * echo cron job
# run at 17:00 weekdays
0 17 * * 1-5 echo cron job
# run at reboot
@reboot echo cron reboot job
File crontab must not contain an EOF characters.
shell, Tcl