Is there an easy (ie via shell commands) way to tell what the DISPLAY 
environment variable is for any given client process?  Sometimes I can 
get what I want by typing ps -axe if:
   a. the client was invoked with a -display argument
      or
   b. DISPLAY is one of the first few variables defined in the environment
      (actually I've never seen b. but it's there to illustrate the type 
      of thing I'm looking for)

Ultimately I wish to determine the number of displays that are simultaneously 
running a given X application.

my system: SunOS 4.1.2 sun4c

thanks for any help,

