Linux is not based on Unix?

[icett]

Just read on wikipedia and come to conclusion that GNU Linux is an entirely different OS from Unix, not based on Unix, not an extention of Unix, having no connection with Unix. But it is Unix like. Is that true? I dont have anything against Linux if it is an entirely different OS from Unix but is Unix like, I think its good that Linux in itself is an OS as strong and stable as Unix is but just want to clarify.:)

[Bachstelze]

GNU's Not Unix.

[kostkon]

Just read on wikipedia and come to conclusion that GNU Linux is an entirely different OS from Unix, not based on Unix, not an extention of Unix, having no connection with Unix. But it is Unix like. Is that true? I dont have anything against Linux if it is an entirely different OS from Unix but is Unix like, I think its good that Linux in itself is an OS as strong and stable as Unix is but just want to clarify.:)
True.

ADDED: for Unix based OSes check the various BSDs.

[MaxIBoy]

Linux was designed to be similar to Minix, which was supposed to be similar to Unix. They share no code in common.

[klange]

The only way Linux is based on Unix is that it shares letters in its name.

However, Linux pretty closely follows POSIX, which came from Unix (when it comes to POSIX, Linux is in the same boat as the BSDs - still not completely compliant, but usually for good reasons).

[tamoneya]

Unix is closed source while linux is open source so there are no relationships at the source code level but they follow similar ideas. They have similar layouts and are laid out similarly.

[OutOfReach]

Linux was designed to be similar to Minix, which was supposed to be similar to Unix. They share no code in common.

True.
http://kerneltrap.org/node/14002

From: Linus Benedict Torvalds [email blocked]
Newsgroups: comp.os.minix
Subject: What would you like to see most in minix?
Date: 25 Aug 91 20:57:08 GMT

Hello everybody out there using minix -

I'm doing a (free) operating system (just a hobby, won't be big and
professional like gnu) for 386(486) AT clones. This has been brewing
since april, and is starting to get ready. I'd like any feedback on
things people like/dislike in minix, as my OS resembles it somewhat
(same physical layout of the file-system (due to practical reasons)
among other things).

I've currently ported bash(1.08) and gcc(1.40), and things seem to work.
This implies that I'll get something practical within a few months, and
I'd like to know what features most people would want. Any suggestions
are welcome, but I won't promise I'll implement them :-)

Linus (torva... at kruuna.helsinki.fi)

PS. Yes - it's free of any minix code, and it has a multi-threaded fs.
It is NOT protable (uses 386 task switching etc), and it probably never
will support anything other than AT-harddisks, as that's all I have :-(.

[mips]

Unix is closed source while linux is open source so there are no relationships at the source code level but they follow similar ideas.

Not true. Not all Unixes are close source. None of the BSDs are and neither is OpenSolaris.

[Bachstelze]

Not true. Not all Unixes are close source. None of the BSDs are and neither is OpenSolaris.

The original AT&T UNIX wasn't. Nowadays, the term designates any OS that complies to the Single UNIX Specification (http://icanhascheezburger.com/2008/08/03/funny-pictures-boring-and-uneventful/), which none of the BSDs, and neither OpenSolaris, do.

[mips]

The original AT&T UNIX wasn't. Nowadays, the term designates any OS that complies to the Single UNIX Specification (http://icanhascheezburger.com/2008/08/03/funny-pictures-boring-and-uneventful/), which none of the BSDs, and neither OpenSolaris, do.

I think you posted the wrong link.

My understanding is/was that the only reason why the BSDs are not certified as Unixes is that it costs a lot of money to get a product certified and it has to be done for each released version. The Open Group owns the Unix trademark and they want money for the certification and use of the name.

http://www.unix.org/version3/
http://en.wikipedia.org/wiki/Single_UNIX_Specification#Non-registered_Unix-like_systems
http://www.opengroup.org/openbrand/Brandfees.htm
http://en.wikipedia.org/wiki/Unix-like#The_term_.E2.80.9CUnix-like.E2.80.9D_and_the_UNIX_trademark
http://www.apuebook.com/faqs.html#4 this is good ;)

[Bachstelze]

Yes ideeed ;) The link that was intended was the one to the Wikipedia page about SUS :

http://en.wikipedia.org/wiki/Single_UNIX_Specification

And yes, the reason most free OSes never ran for the certification is because it would be too expensive, but it is not certain they would get it if they did.

[mips]

...but it is not certain they would get it if they did.

Yes it is not certain but it would be interesting to find out whether they would make it on technical criteria. OSX 10.5 made the criteria and from what I have heard some things work a bit differently there.

[SunnyRabbiera]

For me I dont give a crap, as linux seems to do a good job for what it is.

[nathanscottdaniels]

Don't Linux and Unix share many of the same command-line commands such as chmod and others?

[SunnyRabbiera]

Don't Linux and Unix share many of the same command-line commands such as chmod and others?

Yes indeed.

[Bachstelze]

Don't Linux and Unix share many of the same command-line commands such as chmod and others?

Yes, GNU was intended to be a UNIX clone composed entirely of Free (FSF) Software, so the base utilities have the same name. They are not exactly the same, however, the code is different and there is usually a few usage differences, for example one version canhave an options the other hasn't, or there can be options that behabe slightly differently.

[stream303]

Tracking the pedigree of Linux or any of the BSD's is a great learning experience to see where our joys and failures come from. If we are fortunate, it might help us avoid repeating history. :)

Most OS' at the time had some sort of implementation of standard input and standard output, but it was *nix that brought the revelation of PIPES, which further cemented the "do one thing and do it well" and the "toolbox" approach as opposed to re-inventing the wheel every few years.