Re: administration of initscripts
On Wed, Apr 17, 2013 at 09:51:02PM +0100, Kevin Chadwick wrote:
> And that's a Linux problem where some BSDs put lots of effort into
> compliance only to have the standard changed to suit linux due to
> pressure.
Which standard, POSIX?
> POSIX is a very good thing. Do you disagree? I could perhaps understand
> if there were major benefits.
It's a good thing for helping to write software portable across UNIX
implementations, when that's your goal. It isn't always your goal. It's
slightly less useful if you are only targetting Linux (where LSB is a bit more
useful, but still flawed). It's also quite old, a lot has happened since 2008.
> That's irrelevent as a systemd only linux world (which granted will
> never happen despite lennarts best efforts) would make using Linux more
> difficult for many major products where POSIX is a requirement and
> would damage Linux too as cross polination would be less likely.
Let's explore this scenario in a bit more detail. When is POSIX
mandated? Usually for user-land software written under contract to government
or military, right? In that situation the company is delivering a product to
run on top of an OS. That would not preclude that OS (which the customer has
already got) from using systemd, nor Linux (with it's non-POSIX-compliant
features) nor *BSD (with their non-POSIX-compliant features)… In other words
I cannot see a scenario where this is actually the case.
Does this happen? Or is POSIX compliance only mandated for operating systems
that are deployed/sold to public or military funded projects. In which case
what is important is that POSIX is implemented, not that it is exclusively
implemented — i.e., a *superset* of POSIX functionality is acceptable. And
lucky it is, because all the BSDs implement non-POSIX functionality, not
just Linux. (Although none of free/net/openBSD are actually fully POSIX
compliant anyway: see below)
> Absolute rubbish and SysV is just one of many methods that correctly
> use an init which also differes between systems but can be POSIC
> compliant.
I'd like to see an answer to the question another poster put to you regarding
this: which part of the POSIX specification specifically relates to init
systems?
> So launchd is better than systemd because in this regard because it is
> POSIX compliant.
Do you mean it does not rely on any non-POSIX features? "POSIX compliant"
usually means something else. See e.g.
<http://en.wikipedia.org/wiki/POSIX#Compliant_via_compatibility_feature>, which
lists operating systems which are "Mostly POSIX compliant". Note: Linux is
"mostly", not "fully". Note also, FreeBSD, NetBSD and OpenBSD are "mostly", not
"fully".
> Lennart hasn't got a clue about UNIX. Why not take a true Unix source
> such Brian Kernighan and read "The Practice of Programming" and then
> reconsider.
If you were a faithful follower of Kernighan UNIX philosophy, you wouldn't
touch those nasty BSDs with a bargepole. What we know of as "UNIX" today is
rather an amalgamation of the two — rather different — east and west coast
philosophies.
> Technical arguments such as you can get from the book I have mentioned
> are very important but pass most people by.
It's a great book but it's not to be taken as gospel, and it was written over
14 years ago. More relevant IMHO, but just as much not a panacea, would be "The
Unix Programming Environment", again co-authored by Kernighan, which is over 30
years old.
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