Something

int screens, i;
char *dispstr, *subdisp;
char newdisp[128];

screens = ScreenCount(ecore_x_display_get());

  for (i = 0; i < screens; i++) {
    dispstr = strchr(subdisp, ':');
    if (dispstr) {
      dispstr = strchr(dispstr, '.');
      if (NULL != dispstr)
        *dispstr = '\0';
    }
    snprintf(newdisp, sizeof(newdisp), "%s.%d", subdisp, i);
ecore_x_init(newdisp);