uinput sample

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/input.h>
#include <linux/uinput.h>
#include <errno.h>
#include <string.h>
#include <stdint.h>

#include <cutils/log.h>

#ifndef BUS_VIRTUAL
/* copy from linux/input.h */
#define BUS_VIRTUAL 0x06
#endif


int uinput_create(const char *name, struct keymap *map) {
        struct uinput_user_dev dev;
        int fd, err;

        const char *devs[] = {
                "/dev/uinput",
                "/dev/input/uinput",
                "/dev/misc/uinput",
                NULL,
        };

        while (*devs) {
                fd = open(*devs, O_RDWR);
                if (fd >= 0)
                        break;
        }

        if (fd < 0) {
                err = errno;
                fprintf(stderr, "open error: %s\n", strerror(err));
                return -err;
        }

        memset(&dev, 0, sizeof(dev));
        if (name) strncpy(dev.name, name, UINPUT_MAX_NAME_SIZE - 1);

        dev.id.bustype = BUS_VIRTUAL;
        dev.id.vendor  = 0x0000;
        dev.id.product = 0x0000;
        dev.id.version = 0x0000;

        if (write(fd, &dev, sizeof(dev)) < 0) {
                err = errno;
                fprintf(stderr, "write device information error: %s\n", strerror(err));
                close(fd);
                return -err;
        }


        ioctl(fd, UI_SET_EVBIT, EV_KEY);

        while (map->value != 0xff) {
                ioctl(fd, UI_SET_KEYBIT, map->scancode);
                map++;
        }

        if (ioctl(fd, UI_DEV_CREATE, NULL) < 0) {
                err = errno;
                fprintf(stderr, "write device information error: %s\n", strerror(err));
                close(fd);
                return -err;
        }

        return fd;
}

static void send_event(int fd, uint16_t type, uint16_t code, int32_t value) {
        struct input_event event;
        int err;

        memset(&event, 0, sizeof(event));

        event.type = type;
        event.code = code;
        event.value = value;
        gettimeofday(&event.time, NULL);
        if (write(fd, &event, sizeof(event)) < 0) {
                LOGE("event sent error: %s", strerror(errno));
        }
}

void send_key(int fd, uint16_t key, int press)
{
        LOGW("send key fd = %d, 0x%04x press: %s", fd, key, press ? "true" : "false");
        send_event(fd, EV_KEY, key, press ? 1 : 0);
        send_event(fd, EV_SYN, SYN_REPORT, 0);
}