Mac OS X Leopard is Now Officially Unix

An anonymous reader writes "Mac OS X Leopard is now officially Unix, according to the Opengroup." I know everyone out there was really worried about this one. Welcome to the August news vacuum!

It passed the certification

[morgan_greywolf]

The Open Group's trademark-protected Unix certification program determines who gets to call themselves 'UNIX'. Just because an OS is derived from the original Unix sources at some point doesn't make it a 'UNIX'. You get to call it a 'UNIX' if it passes the Open Group's tests, which determine if it meets the specifications. In this case, Mac OS X 10.5 'Leopard', only when running on Intel Macs, not PPC Macs or any other box was found to meet the UNIX 03 specification.

Re:No Linux?

[Swampash]

Does this mean that OSX is more Unixy than Linux?

As of 10.5, OS X is UNIX. Linux is "UNIX-like".

Correct answers

[morgan_greywolf]

Was Tiger (10.4) certified?

No.

Did Apple even try to certify Tiger?

No.

Why (not)? If not then why start now with Leopard?

Well, if you want certification, you gotta start sometime. I seem to remember the Open Group getting into a little tussle with Apple over Apple's use of the UNIX trademark in its advertisements. The Open Group owns the name UNIX, so you don't get it to call it UNIX unless the Open Group says so. I think this may be part of the arrangement they entered into....

Anyway, the process is expensive. So expensive that none of the *BSDs are certified, no Linux, of course, is certified (yes, a Linux distro could be), etc.

The members of the UNIX club are few: IBM, HP, Sun, NEC, The SCO Group, and a few others.

Re:No Linux?

[Corporate Troll]

No, GNU stands for "GNU's Not Unix". Linux is just Linus first name "unixified".

Re:Good for them

[the_arrow]

Well, the "Single UNIX Specification Version 3" is available to read on the Open Groups website, for free. Registration needed but then if you need to it's easy to download with wget. It contains all of POSIX and more if I'm not misstaken.

Re:Good for them

[Anonymous Coward]

Aren't Single Unix Specifications available? Try http://www.opengroup.org/onlinepubs/000095399/nfin dex.html [opengroup.org] . I suppose you will be asked to 'register' which means entering your name and something similar to your e-mail. I once entered an existing one, and it hasn't even done this e-mail any harm. As I understand it is a standard developed by formally the same committee as POSIX, and it is even formal replacement for it.

Re:I think its a major achievement

[TheRaven64]

Part of the problem with this certification is that it needs to be renewed for each version. For Linux, it's not feasible, because it certifies entire operating systems, rather than kernels. The Single UNIX Specification covers a few basic devices, a huge number of C APIs and a set of useland tools (e.g. shell, C compiler, etc). Linux implements a page or two of the spec, and system calls that allow glibc to implement a load more. The GNU tools implement a lot more beyond that.

A distribution of Linux could apply for certification, but the certification would only be valid for the exact version; update the kernel, any of the GNU utilities, etc, and it would stop being UNIX(TM) (although, for PR purposes, if FooLinux 10 is UNIX, then people probably won't care that FooLinux 10.0.1 hasn't been certified).

The certification is more than just PR, however. Any product that has the certification is guaranteed to comply with the SUS spec. This means any software written to the specification will work. I'm glad OS X is getting it, since there are a few gaps in the implementation on 10.4 that should have been plugged before they got this. I've written code to the SUS spec before, and had it work flawlessly on Solaris but have minor issues on FreeBSD, Linux, and OS X. The more operating systems that conform to SUS, the easier it is to write cross-platform code. Whether they get the certification is irrelevant, to a degree.

Re:Thank goodness!

[Anonymous Coward]

Leopard terminal has tabs :) and cmd-shift-bracket traverses them, just like safari tabs

Nice, my capthca is "quieted" - a sign of things that are about to happen to me?

Re:Good for them

[TheRaven64]

POSIX still costs money, but the last few revisions of POSIX have been the same as the last few revisions of the Single UNIX Specification, which is available for free from The Open Group.

Re:Thank goodness!

[Adnans]

You want tabs? Try iTerm [sourceforge.net]. Horrible name, but it works quite well!

-andy

How expensive is it?

[Savage-Rabbit]

Anyway, the process is expensive. So expensive that none of the *BSDs are certified, no Linux, of course, is certified (yes, a Linux distro could be), etc.

I keep hearing that but I have never actually seen any concrete figures, just various claims ranging from $40.000 or so and up to $500.000 total cost to get certification. I'm assuming that doesn't include the annual license fee for using the brand. So just out of curiosity does anybody have an idea of exactly how expensive getting a Unix 03 certification really is? If the previously cited figures are true the cost of a Unix 03 Cert is peanuts for a company like Apple. If this is really all about getting the Open group to stop complaining about Apple using 'Unix' in it's advertising, as somebody suggested, Apple is probably getting off fairly cheaply plus the certification can only be a plus for the server version of OS.X.

Re:I think its a major achievement

[larkost]

"Unix" (notice the capitol U) is a specific certification whose criteria Apple has met (and paid for the right to use that designation). Generally people refer to things that have their roots in the old Bell Labs UNIX as "unix" or "unix-like" (notice the lower case u's). This is more of a philosophy of how things should work ("everything is a file, even when its not").

Re:Hrrrrm.

[TheRaven64]

Apple aren't selling PowerPC systems anymore. Getting UNIX certification costs money on a per-architecture basis. Getting Leopard certified on PowerPC would cost money, and not enable them to sell any more systems.

Re:I think its a major achievement

[Poltras]

That's a certificate, not just a statement. This means that, following the UNIX 03 Product Standard standards, your program will work on every OSes that supports it. Directories, POSIX, kernel calls, most things should be compliant between the OSes listed in The Open Group. This is a significant advancement for servers (more certificate for an OS is always good in that way), although not really meaningful for desktops.

Re:I think its a major achievement

[Creepy]

Unix is trademarked by the Open Group [unix.org], and so to be Unix, you need to pay them to certify your OS. There are several other similar cases in the industry - POSIX is a biggie, as is OpenGL. Often you'll see OpenGL compatible (like Mesa) or POSIX compatible (like Linux and even MacOS X for a while) - basically, they're saying they're API compatible, but not certified.

Re:It passed the certification

[Guy Harris]

How many of the groups tests for cerification if any, are totally or partially political or financial or contractual in nature ?

Few, if any, as far as I know; the tests are a large pile of code you run on your system, and you pass or fail. There's a licensing fee for the UNIX trademark, and you presumably end up signing a contract to license the trademark.

Why isn't OS X just linux?

Because Linux didn't exist at the time NeXT was founded, OS X is a NEXTSTEP descendant, and it presumably wasn't considered worth the effort to construct OS X and all the frameworks in it atop Linux.

Wont many Linux commands typed into oS x run fine?

Yes, and many Linux commands typed into Solaris will run fine, and many Linux commands typed into AIX will run fine, and many Linux commands typed into {Free,Net,Open,DragonFly}BSD will run fine, and so on. In some cases, that's because the Linux command in question was designed so that {Solaris,AIX,etc.} commands typed into Linux would run fine.

Of what benefit is this to Uses?

It depends on the user. If the user is somebody who has code that expects Single UNIX Standard behavior (e.g., that all the thread-cancellation stuff works), it means their code should work on OS X. If the user is somebody who wants to use an application with that code, it means there might be a better chance that said application will be ported to OS X (although, if the app is a GUI app, it'll either run only with the X server and won't look particularly native, or would have to be ported, or would have to be written with a cross-platform toolkit such as Qt).

what's new ?

UNIX certification.

Re:But it doesn't really do hard links?

[walter_f]

I'm afraid Apple did not even fix the "networked drive" problems in Leopard (being more focused on the iPhone).

Mac OS X users looking forward to another two years or so of merrily spinning beachballs, I presume.

Re:OS X was finally my opportunity to learn UNIX

[Zaurus]

• bash instead of tcsh as the default shell.
• Standard directory names like /home and such.

• This stuff doesn't have to happen at the expense of the GUI either. My impression has been that Terminal.app is more of an accident than an accepted member of the operating system.

bash is the default shell as of Tiger. Your impressions seemed to be based off of Panther.

OS X also has standard directory locations. The unix stuff even sits in standard unix directories (peek into /etc or /bin, for example). Mac-specific stuff is simply stored in a different (non-unix) set of directories than you're used to.

I spend much of my day, every day, in Terminal.app. Works great for me. Love the fact that you can resize the window and long lines reflow themselves. What, exactly, do you not like about the Terminal other than its lack of tabs pre-Leopard?

I'll have to agree with you on Page-up/down, home, and end buttons. They simply work differently on the Mac. I don't use any command-line programs that expects to see those buttons, so it doesn't bother me much. The equivalent of home and end while editing text is command-left and command-right, by the way.

Re:Linux, BSD and Unix certification

[ajs]

Are you aware that the Open Group Unix specifications [opengroup.org] go a lot further than POSIX?

Yes, which is why I made the distinction between merely being POSIX compliant and being Unix certified. The two have radically different scopes.

That said, my bit at the end about the day having dawned where POSIX might need a next pass was aimed at a very post-Unix world where the layer above POSIX that's reasonably standard across Unix-like OSes at this point involves things like networking tools, graphics and other things that were never part of POSIX.

Re:OS X was finally my opportunity to learn UNIX

[nautical9]

bash instead of tcsh as the default shell.

bash has been default since at least Tiger, and I believe Jaguar as well, not that it matters. Choice of a default shell is hardly an advantage, just a difference. I happily used tcsh as my default (interactive) shell for many years, on SunOS and Solaris.

Standard directory names like /home and such.

OS X has standard directories too, just longer ones for their own (and it still has /bin /etc for unix-only apps). Again, not an advantage, just a difference.

Standard text-based package managers like apt-get. My mac friends spend way too much compiling and have all their applications in the weirdest places.

OS X doesn't come with a unix-like package manager out of the box, but Fink [finkproject.org] or Darwin Ports [darwinports.com] suffice for installing any of the few thousand available ports with a single command.

Often things like page up/down and home/end don't work in the OSX versions of programs.

Again, just a difference. Having spent years in the windows/linux camp, I agree it's an annoying change and seems unnecessary, but within a couple days you're used to it.

This stuff doesn't have to happen at the expense of the GUI either. My impression has been that Terminal.app is more of an accident than an accepted member of the operating system.

Speaking as someone who spends most of his day jumping between Vim.app and Terminal.app, I respectfully disagree. It seems plain at first glance, especially compared to most linux terminals, but I'd argue it's just better designed to hide features you rarely need. The single largest omission it's missing is tabs, which are coming in Leopard. But as an avid screen user, I don't really miss them.

I have an Ubuntu linux box, a WinXP box, and PowerBook on my desk. It's the Mac that is the most enjoyable one to use, by far (the others are for added screen real estate and testing).

Re:The Stamp of Stupidity

[david.emery]

Comment's subject line is self-referential, I believe.

Open Group testing is expensive, but I hardly count it as 'extortion'. What's the impact if you don't get their certification? You can't call yourself "Unix". BFD. OpenGroup does require you to pay to implement truth in advertising. (On the other hand, if you think OpenGroup Unix conformance testing is expensive, go check out medical device/drug costs, or even the cost to a University for accreditation...)

Back to the questions raised by the previous post:
> Is Linux on PowerPC (e.g. YellowDog) binary compatible with Linux on x86? I don't think so.....

The goal for the POSIX standards was -source code- compatability. A "strictly conforming application" compiled and executing on one conforming POSIX system is guaranteed to work the same way as the same application on all other conforming POSIX systems (functionally, performance is another matter, of course.) So the answer to "Are systems branded UNIX source compatible?" should be YES, for strictly conforming applications in source code.

What a certificate of conformance means from The Open Group is that the API has been rather thoroughly tested to ensure that it does properly implement the standard. If you get that conformance, then OpenGroup grants you the license to the name Unix(tm). I'm much less thrilled about the Unix branding, than I am about the investment to open standards and standards conformance checking.

I believe that the Unix brand includes more than just the API tests, it also includes shell and utilities. So you can move a shellscript (in sh) from one system to another, and if that shellscript uses only the standard utilities (and their standardized options), and/or compiled conforming applications, it'll do the same thing on POSIX systems ranging from MacOS X to Solaris to HP/UX to AIX. For some of us who have ported software across multiple vendor platforms over the last 10-20 years, that IS A Big Deal.

I've used the term "strictly conforming application" a couple of times. If you're interested in the formal definition (and this term is formally defined in the POSIX standards), you should go read how the standard defines this. Informally, a "strictly conforming application" uses only APIs defined in the standard and depends only on behaviors in the standard (e.g. doesn't depend on some funny return value from a function call.) Or, to be even less formal, strictly conforming applications "color within the lines". A "strictly conforming implementation" is also defined by the standard, and that's what OS X Leopard was tested against. Informally, a strictly conforming application implements the whole standard, including all error return situations, etc. You can NOT implement less than the full standard and be "conforming".

Important Marketing Hype warning: The term 'compliance' has no meaning with respect to POSIX. Normally when a marketing guy says "Our Frobizz 2000 and its BlotzWare OS are POSIX compliant." that usually means "We've implemented some arbitrary subset of the POSIX standards. We are too lazy to implement the whole standard, and if you happen to use some function call that we don't implement, you're shit-outta-luck."

          dave