Shell Programming and Scripting

I need to make a script to start the postfix service on a server when the machine starts up.

I have a script written below, which I think will work, but I am confused on how the rc2.d & rc3.d etc directories actually work.

If I enter the script below, and stick it in the rc3.d directory, will it start the postfix service?

What i am confused on is, does the S25postfix filename tell the system to run the script with the start option? and the K25postfix tell the system to run it with the stop option?

here is the script, will this work if i drop it into the proper rc directories with the K or S prefix?

#!/sbin/sh
#
#
#
#
#START POSTFIX SERVCIES

case "$1" in
'start')
/usr/sbin/postfix start
;;

'stop')
/usr/sbin/postfix stop
;;

*)
echo "Usage: $0 { start | stop }"
;;
esac
exit 0

Yes, you have it exactly right. Ones with a S are run at startup, and ones with a K are run when you do a clean shutdown (obviously not if you just halt the box or it crashes). If you want it to run both at startup and shutdown it should be in the rc2.d or rc3.d - depending on which run level you want it to come up at - with a "S" name, and in rc0.d with a "K" name.

I'm assuming you are on Solaris here I guess. If you are on AIX, HPUX, Linux or some other adjust the numbers to fit your situation. But the basic idea is the same.