一、通过getevent获取按键值，并且模拟操作
# getevent -h
Usage: getevent [-t] [-n] [-s switchmask] [-S] [-v [mask]] [-d] [-p] [-i] [-l] [-q] [-c count] [-r] [device]
    -t: show time stamps
    -n: don't print newlines
    -s: print switch states for given bits
    -S: print all switch states
    -v: verbosity mask (errs=1, dev=2, name=4, info=8, vers=16, pos. events=32, props=64)
    -d: show HID descriptor, if available
    -p: show possible events (errs, dev, name, pos. events)
    -i: show all device info and possible events
    -l: label event types and names in plain text
    -q: quiet (clear verbosity mask)
    -c: print given number of events then exit
    -r: print rate events are received


# getevent -p
add device 1: /dev/input/event3
  name:     "uinput-fpc"
  events:
    KEY (0001): 0067  0069  006a  006c
  input props:
    <none>
add device 2: /dev/input/event2
  name:     "fts"
  events:
    KEY