1/*-
2 * Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/stat.h>
32#include <sys/sysctl.h>
33
34#include <errno.h>
35#include <paths.h>
36#include <stdio.h>
37#include <string.h>
38
39#define	LEN_PATH_DEV	(sizeof(_PATH_DEV) - 1)
40
41char *
42ctermid(char *s)
43{
44	static char def[sizeof(_PATH_DEV) + SPECNAMELEN];
45	struct stat sb;
46	size_t dlen;
47	int sverrno;
48
49	if (s == NULL) {
50		s = def;
51		dlen = sizeof(def) - LEN_PATH_DEV;
52	} else
53		dlen = L_ctermid - LEN_PATH_DEV;
54	strcpy(s, _PATH_TTY);
55
56	/* Attempt to perform a lookup of the actual TTY pathname. */
57	sverrno = errno;
58	if (stat(_PATH_TTY, &sb) == 0 && S_ISCHR(sb.st_mode))
59		(void)sysctlbyname("kern.devname", s + LEN_PATH_DEV,
60		    &dlen, &sb.st_rdev, sizeof(sb.st_rdev));
61	errno = sverrno;
62	return (s);
63}
64
65char *
66ctermid_r(char *s)
67{
68
69	return (s != NULL ? ctermid(s) : NULL);
70}
71