DPMSCapable - returns the DPMS capability of the X server
cc [ flag ... ] file ... -lXext [ library ... ]
#include <X11/extensions/dpms.h>
Bool DPMSCapable ( Display *display );
  - 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).
  - 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.