Date: Mon, 9 Jan 2012 08:17:30 -0800 From: Garrett Cooper <yanegomi@gmail.com> To: Hiroki Sato <hrs@FreeBSD.org> Cc: "dougb@FreeBSD.org" <dougb@FreeBSD.org>, "freebsd-rc@FreeBSD.org" <freebsd-rc@FreeBSD.org> Subject: Re: Making use of set_rcvar. Message-ID: <DCABDDB8-E87F-43A6-ABF1-69AD35915375@gmail.com> In-Reply-To: <20120109.223510.1979757999064039809.hrs@allbsd.org> References: <4F08C95F.6040808@FreeBSD.org> <20120108.081216.1547061187942402256.hrs@allbsd.org> <4F0A22D8.8090206@FreeBSD.org> <20120109.223510.1979757999064039809.hrs@allbsd.org>
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On Jan 9, 2012, at 5:35 AM, Hiroki Sato <hrs@FreeBSD.org> wrote:
> Doug Barton <dougb@FreeBSD.org> wrote
> in <4F0A22D8.8090206@FreeBSD.org>:
>
> do> On 01/07/2012 15:12, Hiroki Sato wrote:
> do> > I am always wondering if defining $rcvar as "${name}_enable" at the
> do> > end of load_rc_config() when $rcvar is undefined is bad idea.
> do> >
> do> > Is there any problem with removing rcvar=... in individual rc.d
> do> > scripts except for non-standard ones (empty or different from
> do> > ${name}_enable)? It looks simpler than writing the same line
> do> > "rcvar=${name}_enable" many times in various places.
> do>
> do> This sounds like a great idea in theory, but in practice it doesn't work
> do> out, for 2 reasons. First, we have a lot of scripts in the base (about
> do> 1/3) that rely on the lack of any rcvar meaning that it gets run
> do> unconditionally. In order to provide backwards compatibility we'd have
> do> to add code to enable things by default that were previously unset.
> do> That's not hard to do, but ....
> do>
> do> The other reason is that for ports, the scripts generally look like this:
> do>
> do> load_rc_config foo
> do>
> do> : ${foo_enable:=NO}
> do>
> do> See the problem?
>
> Removing rcvar=`set_rcvar`, and then adding rcvar="" into scripts
> that need to be run unconditionally would work. However, I have no
> strong opinion about that. I agree that it needs some more code
> anyway and keeping things simple is better.
>
> Doug Barton <dougb@FreeBSD.org> wrote
> in <4F0ABE04.5050503@FreeBSD.org>:
>
> do> > The use of "${name}_enable" does not add measurable overhead, but that
> do> > way more of an existing script might be used as a prototype unchanged.
> do>
> do> I understand what you're saying, and I know that the whole "use
> do> variables wherever we can" thing is all '1337 and computer science'y,
> do> but it's silly. The concept of a universal template that can be copied
> do> and pasted for different services is a pipe dream. There are already
> do> many things that need to be changed in the new script, and not updating
> do> rcvar for a new script causes clear and obvious failure messages.
>
> I prefer to use ${name}_enable because putting the same keyword in
> two places always leads to a stupid typo issue.
+1
Thanks,
-Garrett
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