XkbKeysymToModifiers - Man Page

unsigned int XkbKeysymToModifiers (Display *dpy, KeySym ks);

dpy

connection to X server

ks

keysym of interest

XkbKeysymToModifiers finds the set of modifiers currently bound to the keysym ks on the core keyboard. The value returned is the mask of modifiers bound to the  keysym ks. If no modifiers are bound to the keysym, XkbKeysymToModifiers returns zero; otherwise, it returns the inclusive OR of zero or more of the  following: ShiftMask, ControlMask, LockMask, Mod1Mask, Mod2Mask, Mod3Mask,  Mod4Mask, and Mod5Mask.