| /* 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 tarball for details. |
| */ |
| |
| /* BB_AUDIT SUSv3 compliant */ |
| /* http://www.opengroup.org/onlinepubs/007904975/utilities/tty.html */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include "busybox.h" |
| |
| int tty_main(int argc, char **argv) |
| { |
| const char *s; |
| int silent; /* Note: No longer relevant in SUSv3. */ |
| int retval; |
| |
| xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */ |
| |
| silent = bb_getopt_ulflags(argc, argv, "s"); |
| |
| /* gnu tty outputs a warning that it is ignoring all args. */ |
| bb_warn_ignoring_args(argc - optind); |
| |
| retval = 0; |
| |
| if ((s = ttyname(0)) == NULL) { |
| /* According to SUSv3, ttyname can on fail with EBADF or ENOTTY. |
| * We know the file descriptor is good, so failure means not a tty. */ |
| s = "not a tty"; |
| retval = 1; |
| } |
| |
| if (!silent) { |
| puts(s); |
| } |
| |
| bb_fflush_stdout_and_exit(retval); |
| } |