diff options
Diffstat (limited to 'busybox/coreutils/tty.c')
-rw-r--r-- | busybox/coreutils/tty.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/busybox/coreutils/tty.c b/busybox/coreutils/tty.c new file mode 100644 index 0000000..cd2c784 --- /dev/null +++ b/busybox/coreutils/tty.c @@ -0,0 +1,58 @@ +/* vi: set sw=4 ts=4: */ +/* + * tty implementation for busybox + * + * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/* 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" + +extern int tty_main(int argc, char **argv) +{ + const char *s; + int silent; /* Note: No longer relevant in SUSv3. */ + int retval; + + bb_default_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); +} |