devname.c revision 150065 
1/*
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)devname.c	8.2 (Berkeley) 4/29/95";
36#endif /* LIBC_SCCS and not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: head/lib/libc/gen/devname.c 150065 2005-09-12 19:52:42Z stefanf $");
39
40#include <sys/types.h>
41#include <sys/sysctl.h>
42
43#include <err.h>
44#include <fcntl.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <sys/param.h>
49#include <sys/stat.h>
50
51char *
52devname_r(dev_t dev, mode_t type, char *buf, int len)
53{
54	int i;
55	size_t j;
56	char *r;
57
58	if ((type & S_IFMT) == S_IFCHR) {
59		j = len;
60		i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev));
61		if (i == 0)
62		    return (buf);
63	}
64
65	/* Finally just format it */
66	if (dev == NODEV)
67		r = "#NODEV";
68	else
69		r = "#%c:%d:0x%x";
70	snprintf(buf, len, r,
71	    (type & S_IFMT) == S_IFCHR ? 'C' : 'B', major(dev), minor(dev));
72	return (buf);
73}
74
75char *
76devname(dev_t dev, mode_t type)
77{
78	static char buf[SPECNAMELEN + 1];
79
80	return(devname_r(dev, type, buf, sizeof(buf)));
81}
82