can you check the posix definition of getsid() ?  it certainly was different
to what the x/open stuff now says a few years back.  it didn't meantion
process groups or pgid's, but "session ids" which were only guarenteed to
be unique across sessions (see posix for a definition of "sessions".)  this
usage and definition seems to be quite conflicting to me... one session can
have several process groups attached to it.

hmm... i notice that solaris 2.6's getsid() conforms to x/open while the
2.5 one conforms to my memory of the posix getsid.


(times like this, i really wish i still had the posix.1 standard handy...)