Re: Quick fun question: only set an rc.d variable sometimes?

From: Tatsuki Makino <tatsuki_makino_at_hotmail.com>
Date: Tue, 28 Sep 2021 23:34:31 UTC
The rcscript is a /bin/sh script first, so all of Miroslav's replies are written in man sh.
However, the following differences

> : ${dummy_enable:=no}
> : ${dummy_msg="Nothing started."}

are only mentioned in manpage

>     In the parameter expansions shown previously, use of the colon in the
>     format results in a test for a parameter that is unset or null; omission
>     of the colon results in a test for a parameter that is only unset.

So we would have to read it in depth to realize why. :)

Any missing variables can be made up in the script.

: ${pidfile=${dummy_pidfile-/var/run/dummy.pid}}
if [ -z "${pidfile}" ] ; then
 pidfile='/var/run/dummy.pid'
fi

p.s.
I made a mistake in the address of the email, so I will send it again.
I'm sorry to those who received a duplicate. :)