#include <X11/extensions/XInput.h>
XExtensionVersion *XGetExtensionVersion( Display *display, char *name);
display Specifies the connection to the X server.
name Specifies the extension to be queried. The input extension name is definedin the header file XI.h.
The XGetExtensionVersion request is deprecated and should not be used. Clients issuing a XgetExtensionVersion request will not be able to use MPX features. The XGetExtensionVersion request queries the version of the input extension, and returns an XExtensionVersion structure. This structure contains a major_version and minor_version number which can be compared with constants defined in XI.h. Support for additional protocol requests added to the input extension after its initial release is indicated by a version number corresponding to the added requests. Each version contains all the protocol requests contained by previous versions.
You should use XFree to free the XExtensionVersion structure.
This request returns an XExtensionVersion structure.
typedef struct { int present; short major_version; short minor_version; } XExtensionVersion;