The source code to UNIX is contained in many thousands of
separate files. The set of all the files together comprises the
operating system source code. When AT&T's Unix System
Laboratories wrote UNIX, it created a
literary work protected by Copyright. n1
A chain of owners succeeded AT&T: Santa Cruz Operation, Novell,
Caldera, and finally SCO. n2
The copyright status of the UNIX source has been the subject of
some controversy and at least one prior suit. n3
SCO, however, claims to own "all the rights" to UNIX
source. n4 Only the owner of
the copyright can bring an infringement suit - so this is where SCO
gets its original standing to bring a claim.
The linked graphic is intended to capture both the original creation of UNIX as well as its transfer to the current owner. One file in particular is highlighted and named for use as an example in this presentation.
What's with the ate_utils.c file?
It's the closest thing to a smoking gun that's publicly known. SCO has not made known the particular files that it feels have been infringed, but SCO did show snippets of some files at a trade show. Computer programmers familiar with UNIX-like operating systems identified one of the snippets as coming from the ate_utils.c file.
The contents of the file implement a kernel function called a "mutex spin lock". The contents are what's copyrighted, not the file name; the file may not carry that name in the UNIX source. Here's a copy from the Linux 2.4.20 kernel tree if you're curious.
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