1 .\" Copyright (c) 1993 2 .\" The Regents of the University of California. All rights reserved. 3 .\" 4 .\" Redistribution and use in source and binary forms, with or without 5 .\" modification, are permitted provided that the following conditions 6 .\" are met: 7 .\" 1. Redistributions of source code must retain the above copyright 8 .\" notice, this list of conditions and the following disclaimer. 9 .\" 2. Redistributions in binary form must reproduce the above copyright 10 .\" notice, this list of conditions and the following disclaimer in the 11 .\" documentation and/or other materials provided with the distribution. 12 .\" 3. All advertising materials mentioning features or use of this software 13 .\" must display the following acknowledgement: 14 .\" This product includes software developed by the University of 15 .\" California, Berkeley and its contributors. 16 .\" 4. Neither the name of the University nor the names of its contributors 17 .\" may be used to endorse or promote products derived from this software 18 .\" without specific prior written permission. 19 .\" 20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 .\" SUCH DAMAGE. 31 .\" 32 .\" @(#)devname.3 8.2 (Berkeley) 4/29/95 33 .\" $FreeBSD$ 34 .\" 35 .Dd February 22, 2005 36 .Dt DEVNAME 3 37 .Os 38 .Sh NAME 39 .Nm devname 40 .Nd "get device name" 41 .Sh LIBRARY 42 .Lb libc 43 .Sh SYNOPSIS 44 .In sys/stat.h 45 .In stdlib.h 46 .Ft char * 47 .Fn devname "dev_t dev" "mode_t type" 48 .Ft char * 49 .Fn devname_r "dev_t dev" "mode_t type" "char *buf" "int len" 50 .Sh DESCRIPTION 51 The 52 .Fn devname 53 function returns a pointer to the name of the block or character 54 device in 55 .Pa /dev 56 with a device number of 57 .Fa dev , 58 and a file type matching the one encoded in 59 .Fa type 60 which must be one of 61 .Dv S_IFBLK 62 or 63 .Dv S_IFCHR . 64 To find the right name, 65 .Fn devname 66 asks the kernel via the 67 .Va kern.devname 68 sysctl. 69 If it is unable to come up with a suitable name, 70 it will format the information encapsulated in 71 .Fa dev 72 and 73 .Fa type 74 in a human-readable format. 75 .Pp 76 .Fn devname 77 returns the name stored in a static buffer which will be overwritten 78 on subsequent calls. 79 .Fn devname_r 80 takes a buffer and length as argument to avoid this problem. 81 .Sh EXAMPLES 82 .Bd -literal -compact 83 int fd; 84 struct stat buf; 85 char *name; 86 87 fd = open("/dev/tun"); 88 fstat(fd, &buf); 89 printf("devname is /dev/%s\en", devname(buf.st_rdev, S_IFCHR)); 90 .Ed 91 .Sh SEE ALSO 92 .Xr stat 2 93 .Sh HISTORY 94 The 95 .Fn devname 96 function appeared in 97 .Bx 4.4 . 98