~mmach/netext73/busybox

5 by mmach
1.36.1
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/* vi: set sw=4 ts=4: */
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/*
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 * setconsole.c - redirect system console output
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 *
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 * Copyright (C) 2004,2005  Enrik Berkhan <Enrik.Berkhan@inka.de>
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 * Copyright (C) 2008 Bernhard Reutner-Fischer
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 *
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 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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 */
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//config:config SETCONSOLE
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//config:	bool "setconsole (3.6 kb)"
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//config:	default y
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//config:	help
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//config:	Redirect writes to /dev/console to another device,
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//config:	like the current tty while logged in via telnet.
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//config:	This does not redirect kernel log, only writes
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//config:	from user space.
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//config:
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//config:config FEATURE_SETCONSOLE_LONG_OPTIONS
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//config:	bool "Enable long options"
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//config:	default y
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//config:	depends on SETCONSOLE && LONG_OPTS
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//applet:IF_SETCONSOLE(APPLET_NOEXEC(setconsole, setconsole, BB_DIR_SBIN, BB_SUID_DROP, setconsole))
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//kbuild:lib-$(CONFIG_SETCONSOLE) += setconsole.o
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//usage:#define setconsole_trivial_usage
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//usage:       "[-r] [DEVICE]"
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//usage:#define setconsole_full_usage "\n\n"
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//usage:       "Make writes to /dev/console appear on DEVICE (default: /dev/tty)."
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//usage:   "\n""Does not redirect kernel log output or reads from /dev/console."
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//usage:   "\n"
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//usage:   "\n""	-r	Reset: writes to /dev/console go to kernel log tty(s)"
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/* It was a bbox-specific invention, but SUSE does have a similar utility.
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 * SUSE has no -r option, though.
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 */
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#include "libbb.h"
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int setconsole_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int setconsole_main(int argc UNUSED_PARAM, char **argv)
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{
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	const char *device = CURRENT_TTY;
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	int reset;
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	/* at most one non-option argument */
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	reset = getopt32(argv, "^" "r" "\0" "?1");
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	argv += 1 + reset;
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	if (*argv) {
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		device = *argv;
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	} else {
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		if (reset)
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			device = DEV_CONSOLE;
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	}
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//TODO: fails if TIOCCONS redir is already active to some tty.
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//I think SUSE version first does TIOCCONS on /dev/console fd (iow: resets)
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//then TIOCCONS to new tty?
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	xioctl(xopen(device, O_WRONLY), TIOCCONS, NULL);
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	return EXIT_SUCCESS;
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}