67 lines
1.8 KiB
C
67 lines
1.8 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* tty implementation for busybox
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*
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* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
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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 TTY
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//config: bool "tty"
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//config: default y
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//config: help
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//config: tty is used to print the name of the current terminal to
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//config: standard output.
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//applet:IF_TTY(APPLET(tty, BB_DIR_USR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_TTY) += tty.o
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/* BB_AUDIT SUSv4 compliant */
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/* http://www.opengroup.org/onlinepubs/9699919799/utilities/tty.html */
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//usage:#define tty_trivial_usage
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//usage: ""
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//usage:#define tty_full_usage "\n\n"
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//usage: "Print file name of stdin's terminal"
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//usage: IF_INCLUDE_SUSv2( "\n"
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//usage: "\n -s Print nothing, only return exit status"
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//usage: )
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//usage:
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//usage:#define tty_example_usage
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//usage: "$ tty\n"
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//usage: "/dev/tty2\n"
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#include "libbb.h"
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int tty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int tty_main(int argc UNUSED_PARAM, char **argv)
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{
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const char *s;
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IF_INCLUDE_SUSv2(int silent;) /* Note: No longer relevant in SUSv3. */
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int retval;
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xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */
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IF_INCLUDE_SUSv2(silent = getopt32(argv, "s");)
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IF_INCLUDE_SUSv2(argv += optind;)
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IF_NOT_INCLUDE_SUSv2(argv += 1;)
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/* gnu tty outputs a warning that it is ignoring all args. */
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bb_warn_ignoring_args(argv[0]);
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retval = EXIT_SUCCESS;
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s = xmalloc_ttyname(STDIN_FILENO);
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if (s == NULL) {
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/* According to SUSv3, ttyname can fail with EBADF or ENOTTY.
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* We know the file descriptor is good, so failure means not a tty. */
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s = "not a tty";
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retval = EXIT_FAILURE;
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}
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IF_INCLUDE_SUSv2(if (!silent) puts(s);)
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IF_NOT_INCLUDE_SUSv2(puts(s);)
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fflush_stdout_and_exit(retval);
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}
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