1/* ----------------------------------------------------------------------- *
2 *
3 *   Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
4 *
5 *   Permission is hereby granted, free of charge, to any person
6 *   obtaining a copy of this software and associated documentation
7 *   files (the "Software"), to deal in the Software without
8 *   restriction, including without limitation the rights to use,
9 *   copy, modify, merge, publish, distribute, sublicense, and/or
10 *   sell copies of the Software, and to permit persons to whom
11 *   the Software is furnished to do so, subject to the following
12 *   conditions:
13 *
14 *   The above copyright notice and this permission notice shall
15 *   be included in all copies or substantial portions of the Software.
16 *
17 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
19 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
21 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
22 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24 *   OTHER DEALINGS IN THE SOFTWARE.
25 *
26 * ----------------------------------------------------------------------- */
27
28/*
29 * isatty.c
30 *
31 * Return if this is a tty or not
32 */
33
34#include <errno.h>
35#include <string.h>
36#include <com32.h>
37#include <minmax.h>
38#include <unistd.h>
39#include <klibc/compiler.h>
40#include "file.h"
41
42int isatty(int fd)
43{
44    struct file_info *fp = &__file_info[fd];
45
46    if (fd >= NFILES || !fp->iop) {
47	errno = EBADF;
48	return -1;
49    }
50
51    /* __DEV_TTY == 1 */
52    return (fp->iop->flags & __DEV_TTY);
53}
54