#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <lockdev.h>

#define DEVICE_PATH "/dev/"

int main() {
    struct dirent *entry;
    DIR *dp;
    char device[256];
    int fd;

    dp = opendir(DEVICE_PATH);
    if (dp == NULL) {
        perror("opendir");
        return 1;
    }

    while ((entry = readdir(dp))) {
        if (strncmp(entry->d_name, "tty", 3) == 0 &&
            strcmp(entry->d_name, "tty") != 0 &&
            strcmp(entry->d_name, "tty0") != 0) {

            snprintf(device, sizeof(device), "%s%s", DEVICE_PATH, entry->d_name);
            break;
        }
    }

    closedir(dp);

    if (entry == NULL) {
        fprintf(stderr, "No suitable tty device found (excluding tty and tty0)\n");
        return 1;
    }

    printf("Device in use: %s\n", device);

    fd = open(device, O_RDWR);
    if (fd == -1) {
        perror("open");
        return 1;
    }

    if (dev_lock(device) == -1) {
        perror("dev_lock");
        close(fd);
        return 1;
    }

    printf("Device is locked.\n");

    if (dev_unlock(device, 0) == -1) {
        perror("dev_unlock");
        close(fd);
        return 1;
    }

    printf("Device is unlocked.\n");

    close(fd);
    return 0;
}