1 /* vi: set sw=4 ts=4: */
2 /*
3 * setconsole.c - redirect system console output
4 *
5 * Copyright (C) 2004,2005 Enrik Berkhan <Enrik.Berkhan@inka.de>
6 * Copyright (C) 2008 Bernhard Reutner-Fischer
7 *
8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9 */
10 //config:config SETCONSOLE
11 //config: bool "setconsole (3.6 kb)"
12 //config: default y
13 //config: help
14 //config: Redirect writes to /dev/console to another device,
15 //config: like the current tty while logged in via telnet.
16 //config: This does not redirect kernel log, only writes
17 //config: from user space.
18 //config:
19 //config:config FEATURE_SETCONSOLE_LONG_OPTIONS
20 //config: bool "Enable long options"
21 //config: default y
22 //config: depends on SETCONSOLE && LONG_OPTS
23
24 //applet:IF_SETCONSOLE(APPLET_NOEXEC(setconsole, setconsole, BB_DIR_SBIN, BB_SUID_DROP, setconsole))
25
26 //kbuild:lib-$(CONFIG_SETCONSOLE) += setconsole.o
27
28 //usage:#define setconsole_trivial_usage
29 //usage: "[-r] [DEVICE]"
30 //usage:#define setconsole_full_usage "\n\n"
31 //usage: "Make writes to /dev/console appear on DEVICE (default: /dev/tty)."
32 //usage: "\n""Does not redirect kernel log output or reads from /dev/console."
33 //usage: "\n"
34 //usage: "\n"" -r Reset: writes to /dev/console go to kernel log tty(s)"
35
36 /* It was a bbox-specific invention, but SUSE does have a similar utility.
37 * SUSE has no -r option, though.
38 */
39
40 #include "libbb.h"
41
42 int setconsole_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
setconsole_main(int argc UNUSED_PARAM,char ** argv)43 int setconsole_main(int argc UNUSED_PARAM, char **argv)
44 {
45 const char *device = CURRENT_TTY;
46 int reset;
47
48 /* at most one non-option argument */
49 reset = getopt32(argv, "^" "r" "\0" "?1");
50
51 argv += 1 + reset;
52 if (*argv) {
53 device = *argv;
54 } else {
55 if (reset)
56 device = DEV_CONSOLE;
57 }
58
59 //TODO: fails if TIOCCONS redir is already active to some tty.
60 //I think SUSE version first does TIOCCONS on /dev/console fd (iow: resets)
61 //then TIOCCONS to new tty?
62 xioctl(xopen(device, O_WRONLY), TIOCCONS, NULL);
63 return EXIT_SUCCESS;
64 }
65