sort

[Doug Gwyn]

In article <422 at siswat.UUCP> buck at siswat.UUCP (A. Lester Buck) writes:
>But this [merge sorting with replacement selection] is definitely
>_not_ what Unix sort does, using qsort(3) for all sorts.

As of SVR2, the UNIX "sort" utility definitely did perform n-way merge
sorting with replacement selection.  It used a binary tree for each of
the internal runs being merged, inserting a fresh record from an
external merge input file after each merged record was output.  A
quicksort algorithm (not qsort() from the C library, however) was used
only to produce the initial internal runs.

When did this change?