DPMSCapable - returns the DPMS capability of the X server

display
              Specifies the connection to the X server

       The  DPMSCapable  function  returns  the  Display  Power  Management Signaling (DPMS) capability of the X
       server, either TRUE (capable of DPMS) or FALSE (incapable of DPMS).

       DPMSCapable - returns the DPMS capability of the X server

       True           The DPMSCapable function returns True if the X server is capable of DPMS.

       False          The DPMSCapable function returns True if the X server is incapable of DPMS.

X Version 11                                      libXext 1.3.4                                   DPMSCapable(3)

cc [ flag ... ] file ... -lXext [ library ... ]
       #include <X11/extensions/dpms.h>

       BoolDPMSCapable ( Display *display );