mexas at bristol.ac.uk
Tue Feb 28 12:48:03 UTC 2012
On Tue, Feb 28, 2012 at 01:30:09PM +0100, Jerome Herman wrote:
> On 28/02/2012 12:32, Anton Shterenlikht wrote:
> >On Tue, Feb 28, 2012 at 06:25:37AM -0500, Jerry wrote:
> >>On Tue, 28 Feb 2012 11:03:23 +0000
> >>Anton Shterenlikht articulated:
> >>>On Tue, Feb 28, 2012 at 08:46:51PM +1000, Da Rock wrote:
> >>>>On 02/28/12 19:17, Anton Shterenlikht wrote:
> >>>>>I'm putting together a small presentation
> >>>>>about FreeBSD for our IT support staff.
> >>>>>Is fbsd POSIX compliant? Fully? Partially?
> >>>>>The info here is a bit out of date:
> >>>>Looking at the doc its not that out of date. Just check the 9.x
> >>>Oh.. I see. I only looked in the top table.
> >>>Still, I don't get an idea from the table of
> >>>how close FreeBSD is to full POSIX compliance.
> >>>I guess that's the aim, isn't it?
> >>The answer is rather simple. In your presentation you would simple
> >>indicate that FreeBSD is not fully compliant. You then have the option
> >>of making copies of all the pages referenced in the above URL and
> >>including them in the presentation packet you are supplying to the group
> >>or simply referring them to the above URL. Figuring out which is more
> >>impressive I'll leave up to you.
> >sorry to be a pain.
> >Are we talking 10%, 50%, 90% complete?
> >Does the above page include all tasks
> >that need to be completed? In other words,
> >if all tasks on the above page are ticked,
> >does this aumtomatically give 100% compliance,
> >or is it not that simple?
> It is not that simple, POSIX is more a set of norms than a norm by
> itself. There are Posix aspects that are not in FreeBSD and probably
> never will be, other aspects that do exist in FreeBSD but you should
> definitly not use them as they are painfull to use or flawed or both
> (Posix capabilities for exemple). Also there are systems that do support
> a fair part of Posix, but which are just a pain to use in a Posix
> compatible environment, basically requiring you to code quite a lot of
> tools to have a Posix environment. Basically Windows Server supports
> quite a good deal of Posix norms, and it works well for small projects
> or simple programs, but if you want to create a Posix compliant
> distributed datastore you are in for a hell of a ride. Linux is becoming
> basically the same, in that more and more core system tools have
> dependencies on Linux specific API. (And I won't talk about MacOS X)
> A good way of making a presentation would be to first look at what
> aspects of Posix you need and try to find out where these aspect are
> best supported.
> Now a simple and true enough answer would be to say that FreeBSD has one
> of the broader _and most usable_ Posix support, second only to Solaris.
> (Way better than AIX and on par with HP-UX in my humble opinion). It is
> mostly true in the sense that FreeBSD does support quite a lot of Posix
> norms including the latest ones. It is false int the sense that AIX,
> HP-UX IRIX and quite alot of others have a 100% certified compliance for
> some (quite old now) Posix norms. CF :
> At one point FreeBSD was very close to be fully Posix compliant with
> norm 1.e, then norm 1.e was more or less thrown out the windows, and
> posix norming system pretty much imploded at this time.
> So basically it is quite hard to answer without first knowing exactly
> why you need Posix compliance. It is also worth noting that porting an
> application from one fully compliant OS to another is not always easier
> than porting from that OS to a non compliant one. Quite a lot of
> problems can arise in slightly different interpretations of the norm,
> and quite a lot of assumption that are correct under one system will
> require carefull tweaking and lib binding in another.
> Another thing that is worth noting is that Posix norming system is
> dying, I do not know of one system that has compliance above UNIX03, a
> norm written in 2001...
A very helpful reply, thanks
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