XcupQueryVersion - Returns TOG-CUP protocol version supported by the X server

display   Specifies the connection to the X server

       major_version_return
                 Returns the major version supported by the server

       minor_version_return
                 Returns the minor version supported by the server

XcupQueryVersion  sets  major_version_return  and  minor_version_return  to  the  major and minor TOG-CUP
       protocol version supported by the server. If the TOG-CUP library is compatible with the version  returned
       by  the server, it returns nonzero. If the server does not support the TOG-CUP extension, or if there was
       an error during communications with the server, or if  the  server  and  library  protocol  versions  are
       incompatible,  it  returns  zero. No other Xcup functions may be called before this function. If a client
       violates this rule, the effects of all subsequent Xcup calls that it makes are undefined.

       To get the list of reserved colormap entries, use XcupGetReservedColormapEntries.

       To allocate one or more read-only color cells with RGB values, use XcupStoreColors.

       XcupQueryVersion - Returns TOG-CUP protocol version supported by the X server

XcupGetReservedColormapEntries(3Xext), XcupStoreColors(3Xext),
       ColormapUtilizationPolicyandExtension

X Version 11                                      libXext 1.3.4                              XcupQueryVersion(3)

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

       Status XcupQueryVersion(Display *display,
              int *major_version_return, int *minor_version_return);