If an application is dynamically linked, both the X server and the client-side X
library must contain the Xkb extension in order for the client to use the Xkb
extension capabilities. Therefore a dynamically linked application must check
both the library and the server for compatibility before using Xkb function
calls. A properly written program must check for compatibility between the
version of the Xkb library that is dynamically loaded and the one used when the
application was built. It must then check the server version for compatibility
with the version of Xkb in the library.
If your application is statically linked, you must still check for server
compatibility and may check library compatibility. (It is possible to compile
against one set of header files and link against a different, incompatible,
version of the library, although this should not normally occur.)
Pass the symbolic value XkbMajorVersion in
lib_major_in_out and XkbMinorVersion in
lib_minor_in_out. These arguments represent the version of the library used
at compile time. The
XkbLibraryVersion function backfills the major and minor version numbers of the library used at
run time in
lib_minor_in_out. If the versions of the compile time and run time libraries are
XkbLibraryVersion returns True, otherwise, it returns False.
In addition, in order to use the Xkb extension, you must ensure that the
extension is present in the server and that the server supports the version of
the extension expected by the client. Use
XkbQueryExtension to do this, as described in the next section.