/* vi: set sw=4 ts=4: */ /* * tty implementation for busybox * * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org> * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ /* BB_AUDIT SUSv4 compliant */ /* http://www.opengroup.org/onlinepubs/9699919799/utilities/tty.html */ #include "libbb.h" int tty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tty_main(int argc UNUSED_PARAM, char **argv) { const char *s; IF_INCLUDE_SUSv2(int silent;) /* Note: No longer relevant in SUSv3. */ int retval; xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */ IF_INCLUDE_SUSv2(silent = getopt32(argv, "s");) IF_INCLUDE_SUSv2(argv += optind;) IF_NOT_INCLUDE_SUSv2(argv += 1;) /* gnu tty outputs a warning that it is ignoring all args. */ bb_warn_ignoring_args(argv[0]); retval = EXIT_SUCCESS; s = xmalloc_ttyname(STDIN_FILENO); if (s == NULL) { /* According to SUSv3, ttyname can fail with EBADF or ENOTTY. * We know the file descriptor is good, so failure means not a tty. */ s = "not a tty"; retval = EXIT_FAILURE; } IF_INCLUDE_SUSv2(if (!silent) puts(s);) IF_NOT_INCLUDE_SUSv2(puts(s);) fflush_stdout_and_exit(retval); }