Function XPLMGetVirtualKeyDescription 

pub unsafe extern "C" fn XPLMGetVirtualKeyDescription(
    inVirtualKey: c_char,
) -> *const c_char

XPLMGetVirtualKeyDescription

Given a virtual key code (as defined in XPLMDefs.h) this routine returns a human-readable string describing the character. This routine is provided for showing users what keyboard mappings they have set up. The string may read ‘unknown’ or be a blank or NULL string if the virtual key is unknown.