LXR busybox/console-tools/setconsole.c

   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
  42int setconsole_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  43int 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