> I need to programatically differentiate between 4.0, 4.5 and 5.0
 
 
The variable HPCWD exists on 4.5 and later
The command NEWLINK exists on 5.0 and later (there must be a better way...)
  listfile ;seleq=[object=hfsdir]  'hfsdir' may not be supported on 4.5, definetly
  isn't on 4.0.
 
NOTE:
On the Express 3 release of 5.0 (June?) there are 2 new CI variables:
HPOSVERSION and HPRELEASE version.  These contain the os and
release ids seen in the :SHOWME banner.  Eg.
  :showvar hp@version
  HPOSVERSION = B.79.06   (can't be changed)
  HPRELVERSION = B.79.05  (can't be changed)
  HPVERSION = B.79.05  <== this can be changed in sysgen.
 
Jeff Vance