使用/dev/uinput的簡要介紹（含demo程序）【轉】

轉自：https://blog.csdn.net/zhongkunjia/article/details/75142699

uinput機制有2個很大的優點：

1) 不用自己寫驅動（比如弄個紅外遙控器、車載線控）。

2) 創建/dev/input/eventX節點，在用戶態下向/dev/input/eventX寫入事件，即可模擬鍵盤、鼠標等的事件輸入。

操作流程：

1)打開UInput Device

2)設置UInput Device

3)寫入設備信息

4)創建Input Device

5*)向Input Device發送Event

具體的demo代碼如下：

//uinput-demo.c

 

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <linux/uinput.h>
#include <linux/input.h>


#define KEY_CUSTOM_UP 0x20
#define KEY_CUSTOM_DOWN 0x30


static struct uinput_user_dev uinput_dev;
static int uinput_fd;

int creat_user_uinput(void);
int report_key(unsigned int type, unsigned int keycode, unsigned int value);


int main(int argc, char *argv[])
{
    int ret = 0;
    ret = creat_user_uinput();
    if(ret < 0){
        printf("%s:%d\n", __func__, __LINE__);
        return -1;//error process.
    }

    sleep(10);// help you to 'hexdump -C /dev/input/event[X]' for test.

    report_key(EV_KEY, KEY_A, 1);// Report BUTTON A CLICK - PRESS event
    report_key(EV_KEY, KEY_A, 0);// Report BUTTON A CLICK - RELEASE event

    report_key(EV_KEY, KEY_CUSTOM_UP, 12);
    report_key(EV_KEY, KEY_CUSTOM_UP, 0);

    sleep(5);
    close(uinput_fd);
    return 0;
}


int creat_user_uinput(void)
{
    int i;
    int ret = 0;

    uinput_fd = open("/dev/uinput", O_RDWR | O_NDELAY);
    if(uinput_fd < 0){
        printf("%s:%d\n", __func__, __LINE__);
        return -1;//error process.
    }

    //to set uinput dev
    memset(&uinput_dev, 0, sizeof(struct uinput_user_dev));
    snprintf(uinput_dev.name, UINPUT_MAX_NAME_SIZE, "uinput-custom-dev");
    uinput_dev.id.version = 1;
    uinput_dev.id.bustype = BUS_VIRTUAL;

    ioctl(uinput_fd, UI_SET_EVBIT, EV_SYN);
    ioctl(uinput_fd, UI_SET_EVBIT, EV_KEY);
    ioctl(uinput_fd, UI_SET_EVBIT, EV_MSC);

    for(i = 0; i < 256; i++){
        ioctl(uinput_fd, UI_SET_KEYBIT, i);
    }
    ioctl(uinput_fd, UI_SET_MSCBIT, KEY_CUSTOM_UP);
    ioctl(uinput_fd, UI_SET_MSCBIT, KEY_CUSTOM_DOWN);

    ret = write(uinput_fd, &uinput_dev, sizeof(struct uinput_user_dev));
    if(ret < 0){
        printf("%s:%d\n", __func__, __LINE__);
        return ret;//error process.
    }

    ret = ioctl(uinput_fd, UI_DEV_CREATE);
    if(ret < 0){
        printf("%s:%d\n", __func__, __LINE__);
        close(uinput_fd);
        return ret;//error process.
    }
}

int report_key(unsigned int type, unsigned int keycode, unsigned int value)
{
    struct input_event key_event;
    int ret;

    memset(&key_event, 0, sizeof(struct input_event));

    gettimeofday(&key_event.time, NULL);
    key_event.type = type;
    key_event.code = keycode;
    key_event.value = value;
    ret = write(uinput_fd, &key_event, sizeof(struct input_event));
    if(ret < 0){
        printf("%s:%d\n", __func__, __LINE__);
        return ret;//error process.
    }

    gettimeofday(&key_event.time, NULL);
    key_event.type = EV_SYN;
    key_event.code = SYN_REPORT;
    key_event.value = 0;//event status sync
    ret = write(uinput_fd, &key_event, sizeof(struct input_event));
    if(ret < 0){
        printf("%s:%d\n", __func__, __LINE__);
        return ret;//error process.
    }

    return 0;
}

編譯方法：

root@ubuntu:/home/ubuntu/Documents# gcc uinput-demo.c -o uinput-demo
root@ubuntu:/home/ubuntu/Documents# ls
uinput-demo  uinput-demo.c
root@ubuntu:/home/ubuntu/Documents# ./uinput-demo     ------執行時要用root用戶登入才行

這時，在開個終端，切換到：root@ubuntu:/dev/input#

執行hexdump -C event5  ------event5是創建uinput時生成的節點

10秒到后，顯示結果：

root@ubuntu:/dev/input# hexdump -C event5
00000000  bd 5e 69 59 aa fd 05 00  01 00 1e 00 01 00 00 00  |.^iY............|
00000010  bd 5e 69 59 aa fd 05 00  00 00 00 00 00 00 00 00  |.^iY............|
00000020  bd 5e 69 59 d7 fd 05 00  01 00 1e 00 00 00 00 00  |.^iY............|
00000030  bd 5e 69 59 d7 fd 05 00  00 00 00 00 00 00 00 00  |.^iY............|
00000040  bd 5e 69 59 db fd 05 00  01 00 20 00 0c 00 00 00  |.^iY...... .....|
00000050  bd 5e 69 59 db fd 05 00  00 00 00 00 00 00 00 00  |.^iY............|
00000060  bd 5e 69 59 dd fd 05 00  01 00 20 00 00 00 00 00  |.^iY...... .....|
00000070  bd 5e 69 59 dd fd 05 00  00 00 00 00 00 00 00 00  |.^iY............|
adhexdump: event5: 沒有那個設備
00000080
root@ubuntu:/dev/input# 

也可以打開記事本，再次執行：

root@ubuntu:/home/ubuntu/Documents# ./uinput-demo

10秒到后，就會在記事本里輸入：ad。

 

這樣，就可以通過應用程序的執行模擬鼠標、鍵盤等的輸入事件。