#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <fcntl.h>

#include <sys/ioctl.h>
#include <sys/vt.h>

int main(int argc, char **argv)
{
    int fd;

    unsigned char vtnum;
    bool vtlock;

    if (argc < 3) {
        fprintf(stderr, "Usage: vt_set_lock <vtnum> <lock>\n"
                        "       (use numeric int/bool values)\n");
        exit(EXIT_FAILURE);
    }

    fd = open("/dev/tty0", O_RDWR);
    if (fd < 0) {
        perror("/dev/tty");
        exit(EXIT_FAILURE);
    }

    vtnum = *argv[1]-'0';
    vtlock = !!(*argv[2]-'0');

    /* switch */
    if (ioctl(fd, VT_UNLOCKSWITCH, 1) < 0) {
        perror("VT_UNLOCKSWITCH");
        exit(EXIT_FAILURE);
    }
    if (ioctl(fd, VT_ACTIVATE, vtnum) < 0) {
        perror("VT_ACTIVATE");
        exit(EXIT_FAILURE);
    }

    /* lock */
    if (vtlock) {
        if (ioctl(fd, VT_LOCKSWITCH, 1) < 0) {
            perror("VT_LOCKSWITCH");
            exit(EXIT_FAILURE);
        }
    } else {
        if (ioctl(fd, VT_UNLOCKSWITCH, 1) < 0) {
            perror("VT_UNLOCKSWITCH");
            exit(EXIT_FAILURE);
        }
    }

    return 0;
}