From: Massimo Dal Zotto <dz@cs.unitn.it>

> ps-status.patch
>
>       macros for ps status, used by postgres.c and utility.c.
>       Unfortunately ps status is system dependent and the current
>       code doesn't work on linux. The use of macros confines system
>       dependency to into one file (ps-status.h). Users of other
>       operating systems should check this code and submit new macros.