Is Mac OS X Unix-Based Operating System..?

That must mean that there's root user somewhere 🙂 Right? 🙂

There is indeed: please see
http://www.macosxhints.com/article.php?story=20071025100950309
and
http://www.macobserver.com/tip/2008/06/13.1.shtml

As you are Unix experienced you will be aware that you can do immense amounts of damage as root.

Yes, user ID 0 is root on OS X, just like any other UNIX. And, like many modern Linux distributions, root doesn't have a login by default. You simply cannot login as root, rather you must be logged in as another user, and from there you can use various means to do things "as root" by requesting the privilege.

You can "enable" the root account on a Mac by creating a password for the root account, but there's really nothing for which that's necessary.

See http://support.apple.com/kb/HT1528 for details about the root user account.

QueeenZ wrote:
well it's BSD Unix based OS as far as i know. but Bill did invent DOS 8.3 and 16.3 - file extensions..

No, he did not. In fact he "borrowed" his OS from QDOS.
And even QDOS was based on or "borrowed" from CP/M

And in CP/M, which dates back to the early 1970's, we find the following:
File system
File names consisted of up to 8 characters, a period, then up to three characters as a file name extension (8.3 filename convention).
Bill Gates was a salesman and promoter. He did not invent any OS.

And in truth, Apple also borrowed much from Xerox PARC as did Gates. But that's something else entirely.

That must mean that there's root user somewhere 🙂 Right? 🙂

That not a logical assumption. You are improperly drawing an inference. It does not follow that anything Gates did implies a root user in Leopard. They are completely separate items.
Leopard having a root account has nothing at all to do with Mr. Bill.

Message was edited by: nerowolfe

No, he did not. In fact he "borrowed" his OS from QDOS.

To be completely accurate, Gates bought the rights to QDOS, aka 86-DOS, from Seattle Computer.

Dave Sawyer quoting nerowolfe wrote:
No, he did not. In fact he "borrowed" his OS from QDOS.

To be completely accurate, Gates bought the rights to QDOS, aka 86-DOS, from Seattle Computer.

Which is precisely why I put the word borrowed in quotes.

As I recall, Gates "borrowed" QDOS and led IBM to believe he owned exclusive rights to it. He bought it later after IBM agreed to use it. I believe Gates did not buy exclusive rights to it, but I may be wrong. In any case, Gates did not write DOS. I am not sure Gates is or was ever a programmer.

In the end, SCM was awarded 1 Million dollars for QDOS, as ported to IBM's boxes. SCM was exonerated, and IBM realized from where the OS actually came.

And then Gary Kildall, of DR, who created CP/M, noticed (as did may early users of PC-DOS) that some of the code looked very familiar. Lo! and Behold, much of DOS (PC and MS) was heavily "borrowed" from CP/M. BASIC was also from the mind of Gary - actually one of his students.

I guess this goes all the way back to Ada Lovelace, presumably the world's first computer programmer, and Babbage. Most likely even earlier.

Getting back to the subject of this thread, indirectly, the original Unix OS had to have been written in some language and run on some computer that did not run on Unix. Once, most people programmed in assembler and before that machine code. As noted, many early programs and OSs were written by stringing wires through ferrite beads.

Message was edited by: nerowolfe

Well, "borrowed" to some would imply just taking the features, etc. without compensation (as QDOS did with CP/M), whereas Gates actually purchased the OS.

I believe Gates did not buy exclusive rights to it,

Nope, he did. He first purchased nonexclusive distribution rights for $25,000, then came back and bought exclusive rights for an additional $50,000. After a later legal threat by Seattle Computer when they learned about the pre-existing deal with IBM, Microsoft paid an additional $1M.

'nuff said on the subject. Now we return you to our regularly scheduled programming. 😉

I agree its a rather pointless distinction to try make.

It has been a custom for a very long time, but its not obligatory to the system itself (as J. Jones says).

The shells, RE engines, software libraries, etc., have "built-in" ways of picking out filename extensions, but that's higher-level conventions: the user isn't actually obligated to add an extension for the sake of Unix itself.

a brody wrote:
...Some would argue it isn't Unix because it is more based on BSD Unix, and the Mach kernel. System 1 through 9.2.2 have less of a Unix base, but still having some.

A pretty good place to clarify your understanding of what constitutes UNIX in the present day is simply to be found at unixdotorg . Leopard is, as stated, UNIX 03 certified, so I wouldn't confuse yourself by comparison to BSD Unix which is actually different from OS X.

http://www.opengroup.org/platform/unix_certification/news.tpl?CALLER=public.tpl& gnid=548

nerowolfe wrote:
I guess this goes all the way back to Ada Lovelace, presumably the world's first computer programmer, and Babbage. Most likely even earlier.

I'm not certain I'd count external physical media such as punch cards in this digressions into ancient computing history.

nerowolfe wrote:
Getting back to the subject of this thread, indirectly, the original Unix OS had to have been written in some language and run on some computer that did not run on Unix. Once, most people programmed in assembler and before that machine code. As noted, many early programs and OSs were written by stringing wires through ferrite beads.
Message was edited by: nerowolfe

It was originally written on DEC PDP-7 in assembly, so I guess object code.

Ewen wrote:

nerowolfe wrote:
I guess this goes all the way back to Ada Lovelace, presumably the world's first computer programmer, and Babbage. Most likely even earlier.

I'm not certain I'd count external physical media such as punch cards in this digressions into ancient computing history.

nerowolfe wrote:
Getting back to the subject of this thread, indirectly, the original Unix OS had to have been written in some language and run on some computer that did not run on Unix. Once, most people programmed in assembler and before that machine code. As noted, many early programs and OSs were written by stringing wires through ferrite beads.

It was originally written on DEC PDP-7 in assembly, so I guess object code.

My sardonic comments were just that. My questions were also rhetoric. I have used and programmed PDP 7s, written in and used CP/M and early BASIC. I know the origin of the cryptic "? redo from start" error message.

But the question here has been answered many times.
Yes, Mac OS is a Unix-based OS. The key words are Unix-based. Whether one considers Linux, BSD or even Coherent a Unix system, they are all certainly Unix-based. If you grep you know. If you make dep you know even more.

Message was edited by: nerowolfe

Well, Mac OS X certainly has its roots in UNIX, but remember, nerowoof, that isn't true of Mac OS pre OS X or some of the OSes used in non-Mac Apple products