Booting and Shutting Down the System - Solaris 9 System Administrator - page 47

S at the beginning of an rc script causes the rc program to start the service
at the particular run level (in this example, run level 2) by calling the rc script
with the start argument.
Likewise, the same cron rc script is copied (or linked) into the /etc/rc0.d ,
/etc/rc1.d , and /etc/rcS.d directories and given the name K40cron. The K
at the beginning of an rc script causes the rc program to stop the service at
the particular run level by calling the rc script with the stop argument.
Note that the number included in the names of the cron rc script files are
different. The number provides a method for the rc program to start or stop
services in a particular and consistent order. The rc scripts with lower num-
bers are executed before the rc scripts with higher numbers. This is neces-
sary, as some services might require the presence of other services to operate
properly.
For example, a networking application requires that the networking services
be available. This means that the rc script to start the application should
have a higher number than the rc script to start the networking. In addition,
services should be stopped in reverse order. In the case of a networking appli-
cation, the rc script to stop the application should have a lower number than
the rc script to stop the networking.
A copy of all rc scripts is placed in the /etc/init.d directory. To start or stop
a particular service, the system administrator only has to locate the appro-
priate rc script in a single directory.
Adding rc Scripts
The following procedure should be used to add rc scripts to a new service:
1. Write a shell script that will accept the command-line arguments start
and stop along with the appropriate actions to perform those func-
tions.
2. As the superuser, copy the new rc script to the /etc/init.d directory.
3. Determine the run level at which to start the service (typically 2).
4. Determine the two-digit number to control the start sequence (00
through 99). Look at the other startup rc scripts in the appropriate rc
directory and choose a number that is greater than any required servic-
es but less than any services that will use the new service.
5. Copy or link the new script from the /etc/init.d directory to the
appropriate rc directory, giving it a name starting with S followed by
the selected two-digit number and then the service name.