devname.c revision 165903 
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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)devname.c	8.2 (Berkeley) 4/29/95";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: head/lib/libc/gen/devname.c 165903 2007-01-09 00:28:16Z imp $");
35
36#include <sys/types.h>
37#include <sys/sysctl.h>
38
39#include <err.h>
40#include <fcntl.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <sys/param.h>
45#include <sys/stat.h>
46
47char *
48devname_r(dev_t dev, mode_t type, char *buf, int len)
49{
50	int i;
51	size_t j;
52	char *r;
53
54	if ((type & S_IFMT) == S_IFCHR) {
55		j = len;
56		i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev));
57		if (i == 0)
58		    return (buf);
59	}
60
61	/* Finally just format it */
62	if (dev == NODEV)
63		r = "#NODEV";
64	else
65		r = "#%c:%d:0x%x";
66	snprintf(buf, len, r,
67	    (type & S_IFMT) == S_IFCHR ? 'C' : 'B', major(dev), minor(dev));
68	return (buf);
69}
70
71char *
72devname(dev_t dev, mode_t type)
73{
74	static char buf[SPECNAMELEN + 1];
75
76	return(devname_r(dev, type, buf, sizeof(buf)));
77}
78