[Android]getevent,sendevent,input命令的使用

adb shell 進入avd或者真機後臺：

[b]getevent[/b]
getevent -r -q 監控裝置的sendevent事件

root@android:/ # 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

顯示格式說明

root@android:/ # getevent
/dev/input/event5: 0005 0002 00000001
device的名字：事件型別    鍵碼類別  具體的數值

/dev/input/event5: 0000 0000 00000000

表示一次輸入結束

/*
* Event types
*/

#define EV_SYN            0x00
#define EV_KEY            0x01
#define EV_REL            0x02
#define EV_ABS            0x03
#define EV_MSC            0x04
#define EV_SW            0x05
#define EV_LED            0x11
#define EV_SND            0x12
#define EV_REP            0x14
#define EV_FF            0x15
#define EV_PWR            0x16
#define EV_FF_STATUS        0x17
#define EV_MAX            0x1f
#define EV_CNT            (EV_MAX+1)

二. 具體應用, 比如需要檢視audio jack的事件，也就是耳機的插入

1. 首先確認耳機插入的事件是啥
r

oot@android:/ # getevent -i                                                 
add device 1: /dev/input/event2
  bus:      0000
  vendor    0000
  product   0000
  version   0000
  name:     "pmic8xxx_pwrkey"
  location: "pmic8xxx_pwrkey/input0"
  id:       ""
  version:  1.0.1
  events:
    KEY (0001): 0074 
  input props:
    <none>
.....

add device 5: /dev/input/event10
  bus:      0000
  vendor    0000
  product   0000
  version   0000
  name:     "msm8960-snd-card Headset Jack"
  location: "ALSA"
  id:       ""
  version:  1.0.1
  events:
    SW  (0005): 0002* 0004* 0006  000e  000f  0010 
  input props:
    <none>
add device 6: /dev/input/event9
  bus:      0000
  vendor    0000
  product   0000
  version   0000
  name:     "msm8960-snd-card Button Jack"
  location: "ALSA"
  id:       ""
  version:  1.0.1
  events:
    KEY (0001): 0100  0101  0102  0103  0104  0105  0106  0107 
  input props:
    <none>

2. 輸出 audio jack事件

用的event type是#define EV_SW 0x05

/*
 * Switch events
 */

#define SW_LID            0x00  /* set = lid shut */
#define SW_TABLET_MODE        0x01  /* set = tablet mode */
#define SW_HEADPHONE_INSERT    0x02  /* set = inserted */
#define SW_RFKILL_ALL        0x03  /* rfkill master switch, type "any"
                     set = radio enabled */
#define SW_RADIO        SW_RFKILL_ALL    /* deprecated */
#define SW_MICROPHONE_INSERT    0x04  /* set = inserted */
#define SW_DOCK            0x05  /* set = plugged into dock */
#define SW_LINEOUT_INSERT    0x06  /* set = inserted */
#define SW_JACK_PHYSICAL_INSERT 0x07  /* set = mechanical switch set */
#define SW_VIDEOOUT_INSERT    0x08  /* set = inserted */
#define SW_CAMERA_LENS_COVER    0x09  /* set = lens covered */
#define SW_KEYPAD_SLIDE        0x0a  /* set = keypad slide out */
#define SW_FRONT_PROXIMITY    0x0b  /* set = front proximity sensor active */
#define SW_ROTATE_LOCK        0x0c  /* set = rotate locked/disabled */
#define SW_LINEIN_INSERT    0x0d  /* set = inserted */
#define SW_HPHL_OVERCURRENT    0x0e  /* set = over current on left hph */
#define SW_HPHR_OVERCURRENT    0x0f  /* set = over current on right hph */
#define SW_UNSUPPORT_INSERT    0x10  /* set = unsupported device inserted */
#define SW_MAX            0x20
#define SW_CNT            (SW_MAX+1)
root@android:/ # getevent  /dev/input/event10 

0005 0002 00000001 (0002  表示earphone)
0005 0004 00000001 (0004  表示microphone)
0000 0000 00000000

 	插入	拔出
Headset	0005 0002 00000001
0005 0004 00000001
0000 0000 00000000	0005 0002 00000000
0005 0004 00000000
0000 0000 00000000
Headphone	0005 0002 00000001
0000 0000 00000000	0005 0002 00000000
0000 0000 00000000
invalid	0005 0010 00000001
0000 0000 00000000	0005 0010 00000000
0000 0000 00000000

三、具體應用, 比如需要檢視touch的事件
1、確認touch事件路徑

root@android:/ # getevent -i
add device 13: /dev/input/event7
bus: 0000
vendor 0000
product 0000
version 0000
name: "cyttsp4_mt"
location: "cyttsp4_mt.main_ttsp_core"
id: ""
version: 1.0.1
events:
ABS (0003): 0000 : value 0, min 0, max 0, fuzz 0, flat 0, resolution 0
2、touch 事件

用的event type是#define EV_ABS 0x03

只分析多touch事件
#define ABS_MT_SLOT 0x2f /* MT slot being modified */
#define ABS_MT_TOUCH_MAJOR 0x30 /* Major axis of touching ellipse */
#define ABS_MT_TOUCH_MINOR 0x31 /* Minor axis (omit if circular) */
#define ABS_MT_WIDTH_MAJOR 0x32 /* Major axis of approaching ellipse */
#define ABS_MT_WIDTH_MINOR 0x33 /* Minor axis (omit if circular) */
#define ABS_MT_ORIENTATION 0x34 /* Ellipse orientation */
#define ABS_MT_POSITION_X 0x35 /* Center X ellipse position */
#define ABS_MT_POSITION_Y 0x36 /* Center Y ellipse position */
#define ABS_MT_TOOL_TYPE 0x37 /* Type of touching device */
#define ABS_MT_BLOB_ID 0x38 /* Group a set of packets as a blob */
#define ABS_MT_TRACKING_ID 0x39 /* Unique ID of initiated contact */
#define ABS_MT_PRESSURE 0x3a /* Pressure on contact area */
#define ABS_MT_DISTANCE 0x3b /* Contact hover distance */
root@android:/ # getevent /dev/input/event7
單點觸控
0003 0039 000000d5 //觸點區分的唯一ID
0003 0035 00000165 //觸點的x座標
0003 0036 000002fa //觸點的y座標
0003 003a 00000025 //觸點的壓力，實際上是接觸區域大小
0000 0000 00000000 //結束

多點觸控

0003 0039 000000de
0003 0035 00000140
0003 0036 0000047f
0003 003a 00000021
0000 0000 00000000
0003 0035 0000013f
0003 003a 00000027
0003 002f 00000001 //切換上報其中一點
0003 0039 000000df
0003 0035 000001fd
0003 0036 000001e3
0003 003a 00000022
0000 0000 00000000
0003 002f 00000000 //切換上報其中一點
0003 0036 0000047e
0003 003a 0000002b
0000 0000 00000000
0003 0036 0000047d
0003 003a 0000002f
0000 0000 00000000
0003 0036 0000047b
0003 003a 00000034
0003 002f 00000001 //切換上報其中一點
0003 0035 000001fc
0003 0036 000001e6
0003 003a 00000023
0000 0000 00000000

三、getevent 原始碼分析
＠system/core/toolbox/getevent.c
int getevent_main(int argc, char *argv[])

{

const char *device_path = "/dev/input"; //讀取的路徑

....

res = scan_dir(device_path, print_flags); //掃描路徑下的所有檔案路徑

....

while(1) {

...
res = read(ufds[i].fd, &event, sizeof(event)); //讀取事件
...

print_event(event.type, event.code, event.value, print_flags); //列印出事件資訊
}
}

四、sendevent原始碼分析

@system/core/toolbox/sendevent.c

[b]sendevent[/b]
1. 模擬插入耳機， 這時候可以啟動收音機了（不再有耳機沒有的提示框）
sendevent /dev/input/event10 0005 0002 00000001

sendevent /dev/input/event10 0000 0000 00000000


[b]input[/b] 根據avd和真機的不同，引數可能不同

$ input
usage: input [text|keyevent]
input text <string>
input keyevent <event_code>

[b]4.可能遇到的問題[/b]
實際實現的時候，還可能遇到問題
一是root，getevent和sendevent需要/dev/input/event*的許可權。一般應用是沒有這個許可權的，需要在程式裡面獲取su後，執行chmod 666 /dev/input/event*。
二是裝置名稱。因為你不知道觸控式螢幕或者按鍵到底對應的event*是多少。需要有一個初始化的過程，大致思路是往event0-event9分別寫入按鍵和觸控訊號，同時監聽activity裡的onkeydown和view的onclick，這樣來偵測裝置。
三是廠商的實現不一樣，這個沒辦法，只能一個一個適配了，一般來說都還是標準的，有些廠商會有單獨的實現。
參考
http://lxr.free-electrons.com/source/include/uapi/linux/input.h#L803
http://source.android.com/tech/input/touch-devices.html
http://cjix.info/blog/misc/internal-input-event-handling-in-the-linux-kernel-and-the-android-userspace/


推薦參考網址：http://www.jtben.com/document/919575