| /* 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 */ |
| |
| //usage:#define tty_trivial_usage |
| //usage: "" |
| //usage:#define tty_full_usage "\n\n" |
| //usage: "Print file name of stdin's terminal" |
| //usage: IF_INCLUDE_SUSv2( "\n" |
| //usage: "\nOptions:" |
| //usage: "\n -s Print nothing, only return exit status" |
| //usage: ) |
| //usage: |
| //usage:#define tty_example_usage |
| //usage: "$ tty\n" |
| //usage: "/dev/tty2\n" |
| |
| #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); |
| } |