w32 support for POSIX functions

I understand that some PSPP users run it under Windows.  So far,
I've avoided using non-ANSI C functions as much as possible.
However, in a patch I'm going to check in sometime today, I'm
introducing the use of POSIX (but not ANSI) functions open(),
read(), write(), lseek(), and close().  Do Windows runtime
libraries support these functions?

-- 
Anyone who cannot cope with mathematics is not fully human.  At best he
is a tolerable subhuman who has learned to wear shoes, bathe and not
make messes in the house.
                -- Lazarus Long, "Time Enough for Love"