sbase/chvt.c

62 lines
1001 B
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include "util.h"
enum {
/* from <linux/vt.h> */
VT_ACTIVATE = 0x5606,
VT_WAITACTIVE = 0x5607,
/* from <linux/kd.h> */
KDGKBTYPE = 0x4B33
};
char *vts[] = {
"/proc/self/fd/0",
"/dev/console",
"/dev/tty",
"/dev/tty0",
};
static void
usage(void)
{
eprintf("usage: chvt N\n");
}
int
main(int argc, char **argv)
{
int n, i, fd;
char c;
if(argc!=2 || strspn(argv[1], "1234567890") != strlen(argv[1]))
usage();
n = atoi(argv[1]);
for(i = 0; i < LEN(vts); i++) {
fd = open(vts[i], O_RDONLY);
if(fd < 1)
continue;
c = 0;
if(ioctl(fd, KDGKBTYPE, &c) == 0)
goto VTfound;
close(fd);
}
eprintf("chvt: couldn't find a console.\n");
VTfound:
if(ioctl(fd, VT_ACTIVATE, n) == -1)
eprintf("chvt: VT_ACTIVATE '%d':", n);
if(ioctl(fd, VT_WAITACTIVE, n) == -1)
eprintf("chvt: VT_WAITACTIVE '%d':", n);
close(fd);
return 0;
}