1/* See LICENSE file for copyright and license details. */
 2
 3
 4#include <sys/types.h>
 5#include <sys/stat.h>
 6#include <sys/ioctl.h>
 7
 8#include <fcntl.h>
 9#include <stdio.h>
10#include <string.h>
11#include <unistd.h>
12
13#include "util.h"
14
15#define CONSOLE "/dev/console"
16
17#define VT_LOCKSWITCH   0x560B  /* disallow vt switching */
18#define VT_UNLOCKSWITCH 0x560C  /* allow vt switching */
19
20static void
21usage(void)
22{
23	eprintf("usage: %s n | y\n", argv0);
24}
25
26// ?man vtallow: allow non-root vt access
27// ?man arguments: n | y
28// ?man allow non-root users to access virtual terminal devices
29int
30main(int argc, char *argv[])
31{
32	int fd;
33	int allow;
34
35	ARGBEGIN {
36	default:
37		usage();
38	} ARGEND;
39
40	if (argc != 1)
41		usage();
42
43	if (!strcmp(argv[0], "y"))
44		allow = 1;
45	else if (!strcmp(argv[0], "n"))
46		allow = 0;
47	else
48		usage();
49
50	if ((fd = open(CONSOLE, O_WRONLY)) < 0)
51		eprintf("open %s:", CONSOLE);
52	if (ioctl(fd, allow ? VT_UNLOCKSWITCH : VT_LOCKSWITCH) < 0)
53		eprintf("cannot %s VT switch:",
54			allow ? "unlock" : "lock");
55	close(fd);
56	return 0;
57}