1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini fgconsole implementation for busybox
4  *
5  * Copyright (C) 2010 by Grigory Batalov <bga@altlinux.org>
6  *
7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8  */
9 //config:config FGCONSOLE
10 //config:	bool "fgconsole (1.5 kb)"
11 //config:	default y
12 //config:	help
13 //config:	This program prints active (foreground) console number.
14 
15 //applet:IF_FGCONSOLE(APPLET_NOEXEC(fgconsole, fgconsole, BB_DIR_USR_BIN, BB_SUID_DROP, fgconsole))
16 
17 //kbuild:lib-$(CONFIG_FGCONSOLE) += fgconsole.o
18 
19 //usage:#define fgconsole_trivial_usage
20 //usage:	""
21 //usage:#define fgconsole_full_usage "\n\n"
22 //usage:	"Get active console"
23 
24 #include "libbb.h"
25 
26 /* From <linux/vt.h> */
27 struct vt_stat {
28 	unsigned short v_active;        /* active vt */
29 	unsigned short v_signal;        /* signal to send */
30 	unsigned short v_state;         /* vt bitmask */
31 };
32 enum { VT_GETSTATE = 0x5603 }; /* get global vt state info */
33 
34 int fgconsole_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
fgconsole_main(int argc UNUSED_PARAM,char ** argv UNUSED_PARAM)35 int fgconsole_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
36 {
37 	struct vt_stat vtstat;
38 
39 	vtstat.v_active = 0;
40 	xioctl(get_console_fd_or_die(), VT_GETSTATE, &vtstat);
41 	printf("%d\n", vtstat.v_active);
42 
43 	return EXIT_SUCCESS;
44 }
45