XNoOp - No Operation

display   Specifies the connection to the X server.

       The  XNoOp  function  sends  a  NoOperation  protocol  request  to  the  X server, thereby exercising the
       connection.

       XNoOp - No Operation

Xlib-CLanguageXInterface

X Version 11                                      libX11 1.8.12                                         XNoOp(3)

       int XNoOp(Display *display);