ubase/chvt.c
FRIGN b6669b5f19 Refactor chvt(1)
1) Properly implement arg.h.
2) Use estrtonum instead of estrtol.
3) Check close().
4) Small fixes.
5) Update manpage.
2015-09-07 11:47:10 +01:00

68 lines
1.1 KiB
C

/* See LICENSE file for copyright and license details. */
#include <sys/ioctl.h>
#include <sys/types.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "util.h"
#define KDGKBTYPE 0x4B33 /* get keyboard type */
#define VT_ACTIVATE 0x5606 /* make vt active */
#define VT_WAITACTIVE 0x5607 /* wait for vt active */
static char *vt[] = {
"/proc/self/fd/0",
"/dev/console",
"/dev/tty",
"/dev/tty0",
};
static void
usage(void)
{
eprintf("usage: %s num\n", argv0);
}
int
main(int argc, char *argv[])
{
unsigned int n, i;
int fd;
char c;
ARGBEGIN {
default:
usage();
} ARGEND;
if (argc != 1)
usage();
n = estrtonum(argv[0], 0, UINT_MAX);
for (i = 0; i < LEN(vt); i++) {
if ((fd = open(vt[i], O_RDONLY)) < 0)
continue;
c = 0;
if (ioctl(fd, KDGKBTYPE, &c) == 0)
goto found;
if (close(fd) < 0)
eprintf("close %s:", vt[i]);
}
eprintf("no console found\n");
found:
if (ioctl(fd, VT_ACTIVATE, n) == -1)
eprintf("VT_ACTIVATE %u:", n);
if (ioctl(fd, VT_WAITACTIVE, n) == -1)
eprintf("VT_WAITACTIVE %u:", n);
if (close(fd) < 0)
eprintf("close %s:", vt[i]);
return 0;
}