目标键位：Caps Lock映射为Control L，Control L映射为Escape，Escape映射为Caps Lockspa
方法：修改/usr/share/X11/xkb/keycodes/evdev，使code
<CAPS> = 9 <LCTL> = 66 <ESC> = 37blog
执行 sudo dpkg-reconfigure xkb-data 即生效io
注：很明显，只在X Window下生效class