linux 获取 按键状态

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

int main(int argc, char *argv[]) {
    struct libevdev *dev = NULL;
    int fd;

    if (argc < 2) {
        fprintf(stderr, "Usage: %s /dev/input/eventX\n", argv[0]);
        return 1;
    }

    fd = open(argv[1], O_RDONLY | O_NONBLOCK);
    if (fd < 0) {
        perror("Failed to open input device");
        return 1;
    }

    if (libevdev_new_from_fd(fd, &dev) < 0) {
        fprintf(stderr, "Failed to init libevdev\n");
        close(fd);
        return 1;
    }

    while (1) {
        struct input_event ev;
        int rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_NORMAL, &ev);
        if (rc == LIBEVDEV_READ_STATUS_SUCCESS) {
            if (ev.type == EV_KEY) {
                printf("Key %d %s\n", ev.code, ev.value ? "pressed" : "released");
            }
        } else if (rc == LIBEVDEV_READ_STATUS_SYNC) {
            continue;
        } else {
            break;
        }
    }

    libevdev_free(dev);
    close(fd);
    return 0;
}

gcc -o key_reader key_reader.c -levdev
sudo ./key_reader /dev/input/eventX