Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [unix]

Unix is the topic of this site. Do not use this tag except for questions about the historical UNIX product.

Unix in general is the topic of this site. Do not use this tag unless your question is about the historical UNIX product from AT&T. If your question is about a particular unix variant (e.g. , , , …) or a particular application, use the corresponding tag. Otherwise stick to one or more tags reflecting what you are trying to do.

Unix is an operating system that was initially developed at AT&T Bell Labs as a simpler Multics. Since then, there have been many operating systems based on Unix, at least reproducing the interfaces if not the design and sometimes the code.

Legal status

The original Unix code is proprietary software, originally owned by AT&T and licensed by several companies. This spurned several groups into developing independent code bases with similar design. The best known are and .

UNIX® is a registered trade mark owned by The Open Group. Only certified products may use the brand.

In informal usage, “unix” or “Unix” or “Un*x” or “*nix” can mean any Unix-like system, whether it is derived from the original code or not, and whether it has the brand or not.

Standards

The POSIX and Single UNIX standards codify many interfaces for programmers and command-line users.

System administration is not so standardized and varies greatly from one variant to the next. (See the Rosetta Stone for Unix for an overview.)

Unix variants

Derived from the original Unix code:

Derived from BSD:

Others:

POSIX emulation layers on non-unix operating systems:

(And many more that have not (yet) been discussed on this site.)

Further reading

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Is Linux a Unix?

So, there are lots of different versions of Unix out there: HP-UX, AIX, BSD, etc. Linux is considered a Unix clone rather than an implementation of Unix. Are all the "real" Unices actual descendants of the original? If not, what separates Linux from…
Shawn J. Goff
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Why is there a * When There is Mention of Unix Throughout the Internet?

I've noticed that throughout the Internet, within forums and blog posts, Unix always has a * in the word, whether it is *nix or Un*x, as I noticed at the welcoming banner at the Unix StackExchange site. Why is this like this?
JFW
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What aspects of Plan 9 have made their way into Unix?

Plan 9 was developed by Bell Labs as a successor to Unix. Although for various reasons it never quite materialized as such, a fair amount of development still went into Plan 9. My question is, what - if anything - from Plan 9 has made its way into…
Justin Ethier
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What does 'uni' mean in unistd.h

What does uni mean in unistd.h Does it mean unix? or universal? What is it?
Benjamin
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Expansion of the word UNIX?

Is UNIX an acronym? What does it stand for?
Renjith G
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"Linux supports the dynamic loading of kernel modules. "

I read in a book written by Robert Love that: Linux supports the dynamic loading of kernel modules. He said this is the difference between Linux and Unix, but I seem to recall there is also KLD in FreeBSD? So can KLD also be seen as dynamic…
Andy Leman
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What should every expert know?

What things should any self-professed UNIX expert have under their belt? I'm looking to fill any gaps in my knowledge. Some things I can think of off the bat: Shell (interactive and scripting) Common utilities (grep, ls, etc.) vi (possibly Emacs…
tsvallender
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