Dr. Korn's one liner seems to have been written in the days of K&R C. LivinFree uses HP-UX. HP-UX includes a old K&R C compiler for free as part of the OS. I am sure that he is using this compiler to compile the one liner.

The old C preprocessor seems to set the symbol "unix" to be "1" for some odd reason. And I guess that ansi cleaned up the name space. I never noticed this before and now I wonder what old C compilers did on, say, an old IBM pc. Set unix to 0? Or leave unix undefined and set ms-dos to 1?

In any event, I got the one liner to work with ansi C by adding a line "#define unix 1".