xref: /freebsd/lib/libc/gen/devname.c (revision 5c52a79884070364bfc920fb8e492cfac61ec72f)
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)
31 static char sccsid[] = "@(#)devname.c	8.2 (Berkeley) 4/29/95";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
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 
47 char *
48 devname_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 
71 char *
72 devname(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