TUHS November 2024

tuhs@tuhs.org

24 participants
11 discussions

IBM's involvement (was: SCO's "evidence" (was: RIP Darl McBride former CEO of SCO))

by Douglas McIlroy

As a bit-part expert witness for the other side of the SCO case, I saw hundreds of pages of evidence in the form of side-by-side code comparison. As I recall, the vast majority of highlighted correspondences were small snippets, often rearranged. I didn't interact with the lawyers enough to form a solid opinion about where this stood on the spectrum of coincidence to fair use to plagiarism. It certainly wasn't wholesale copying. I do not recall being asked to opine on whether trade secrets had been stolen. Apropos of rearranged snippets, one of the diff algorithms I experimented with in the mid-70s identified rearrangements. I abandoned it because real life code contains lots of similar lines, so many in PDP-11 assembler programs as to suggest that these programs are largely permutations of each other. The phenomenon is much less common in C, but still present; witness the prevalence of code like int i, n; for(i=0; i<n; i++) { The phenomenon may have been afoot in the SCO evidence. In regard to trade secrets, I was surprised when I moved from Unix at Bell Labs to Linux at Dartmouth and found calendar(1) to be completely rewritten, but with logic absolutely identical to the original version I wrote at the Labs. That was so idiosyncratic that the identity of the two could not have been an accident. Doug

1 month, 2 weeks

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TUHS November 2024