[CentOS] Cemtos 7 : Systemd alternatives ?

[Jonathan Billings]

On Tue, Jul 15, 2014 at 10:01:34AM -0500, Les Mikesell wrote:
>
> On Mon, Jul 14, 2014 at 11:50 PM, Keith Keller
> <kkeller at wombat.san-francisco.ca.us> wrote:
> >>>
> >> 1. See the systemd myths web page
> >> http://0pointer.de/blog/projects/the-biggest-myths.html
> >
> > In the interest of full disclosure, that page is written by one of the
> > primary authors of systemd, so we shouldn't expect an unbiased opinion.
> > (Not saying it's wrong, only that it's important to understand the
> > perspective an author might have.)
> 
> One thing that bothers me very much when reading that is the several
> mentions of how you don't need to learn shell syntax as though that is
> an advantage or as if the author didn't already know and use it
> already.   As if he didn't understand that _every command you type at
> the command line_ is shell syntax.   Or as if he thinks learning a
> bunch of special-case language quirks is somehow better than one that
> you can use in many other situations.  When you get something that
> fundamental wrong it is hard to take the rest seriously.

You mean this paragraph?

"systemd certainly comes with a learning curve. Everything
does. However, we like to believe that it is actually simpler to
understand systemd than a Shell-based boot for most people. Surprised
we say that? Well, as it turns out, Shell is not a pretty language to
learn, it's syntax is arcane and complex. systemd unit files are
substantially easier to understand, they do not expose a programming
language, but are simple and declarative by nature. That all said, if
you are experienced in shell, then yes, adopting systemd will take a
bit of learning."

I think the point is that systemd unit file syntax is significantly
simpler than shell syntax -- can we agree on that?  It also is
significantly less-featureful than a shell programming language.  Yes,
you're going to be using shell elsewhere, but in my experience, the
structure of most SysVinit scripts is nearly identical, and where it
deviates is where things often get confusing to people not as familiar
with shell scripting.  Many of the helper functions in
/etc/rc.d/init.d/functions seem to exist to STOP people from writing
unique shell code in their init scripts.

-- 
Jonathan Billings <billings at negate.org>