/* Send a fake keystroke event to an X window. */

/* by Adam Pierce  (http://doctort.org/adam/nerd-notes/x11-fake-keypress-event.html) 
   modified by Björn Lindström <bkhl@elektrubadur.se> */

/* Compile with
   g++ -o XFakeKey XFakeKey.C -L/usr/X11R6/lib -lX11 */

#include <X11/Xlib.h>
#include <X11/keysym.h>

/* The key code to be sent. A full list of available codes can be
found in /usr/include/X11/keysymdef.h */
#define KEYCODE XK_t
#define MODIFIERS ControlMask

/* Function to create a keyboard event */
XKeyEvent createKeyEvent(Display *display, Window &win,
                         Window &winRoot, bool press,
                         int keycode, int modifiers)
{
  XKeyEvent event;
  event.display     = display;
  event.window      = win;
  event.root        = winRoot;
  event.subwindow   = None;
  event.time        = CurrentTime;
  event.x           = 1;
  event.y           = 1;
  event.x_root      = 1;
  event.y_root      = 1;
  event.same_screen = True;
  event.keycode     = XKeysymToKeycode(display, keycode);
  event.state       = modifiers;
  if(press)
    event.type = KeyPress;
  else
    event.type = KeyRelease;
  return event;
}

main()
{
  /* Obtain the X11 display. */
  Display *display = XOpenDisplay(0);
  if(display == NULL)
    return -1;
  /* Get the root window for the current display. */
  Window winRoot = XDefaultRootWindow(display);
  /* Find the window which has the current keyboard focus. */
  Window winFocus;
  int    revert;
  XGetInputFocus(display, &winFocus, &revert);
  /* Send a fake key press event to the window. */
  XKeyEvent event = createKeyEvent(display, winFocus, winRoot, true, KEYCODE, MODIFIERS);
  XSendEvent(event.display, event.window, True, KeyPressMask, (XEvent *)&event);
  /* Send a fake key release event to the window. */
  event = createKeyEvent(display, winFocus, winRoot, false, KEYCODE, MODIFIERS);
  XSendEvent(event.display, event.window, True, KeyPressMask, (XEvent *)&event);
  /* Done. */
  XCloseDisplay(display);
  return 0;
}