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.\" 4. Neither the name of the University nor the names of its contributors
13.\" may be used to endorse or promote products derived from this software
14.\" without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\" @(#)devname.3 8.2 (Berkeley) 4/29/95
29.\" $FreeBSD: head/lib/libc/gen/devname.3 165903 2007-01-09 00:28:16Z imp $
30.\"
31.Dd February 22, 2005
32.Dt DEVNAME 3
33.Os
34.Sh NAME
35.Nm devname
36.Nd "get device name"
37.Sh LIBRARY
38.Lb libc
39.Sh SYNOPSIS
40.In sys/stat.h
41.In stdlib.h
42.Ft char *
43.Fn devname "dev_t dev" "mode_t type"
44.Ft char *
45.Fn devname_r "dev_t dev" "mode_t type" "char *buf" "int len"
46.Sh DESCRIPTION
47The
48.Fn devname
49function returns a pointer to the name of the block or character
50device in
51.Pa /dev
52with a device number of
53.Fa dev ,
54and a file type matching the one encoded in
55.Fa type
56which must be one of
57.Dv S_IFBLK
58or
59.Dv S_IFCHR .
60To find the right name,
61.Fn devname
62asks the kernel via the
63.Va kern.devname
64sysctl.
65If it is unable to come up with a suitable name,
66it will format the information encapsulated in
67.Fa dev
68and
69.Fa type
70in a human-readable format.
71.Pp
72.Fn devname
73returns the name stored in a static buffer which will be overwritten
74on subsequent calls.
75.Fn devname_r
76takes a buffer and length as argument to avoid this problem.
77.Sh EXAMPLES
78.Bd -literal -compact
79int fd;
80struct stat buf;
81char *name;
82
83 fd = open("/dev/tun");
84 fstat(fd, &buf);
85 printf("devname is /dev/%s\en", devname(buf.st_rdev, S_IFCHR));
86.Ed
87.Sh SEE ALSO
88.Xr stat 2
89.Sh HISTORY
90The
91.Fn devname
92function appeared in
93.Bx 4.4 .
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.\" 4. Neither the name of the University nor the names of its contributors
13.\" may be used to endorse or promote products derived from this software
14.\" without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\" @(#)devname.3 8.2 (Berkeley) 4/29/95
29.\" $FreeBSD: head/lib/libc/gen/devname.3 165903 2007-01-09 00:28:16Z imp $
30.\"
31.Dd February 22, 2005
32.Dt DEVNAME 3
33.Os
34.Sh NAME
35.Nm devname
36.Nd "get device name"
37.Sh LIBRARY
38.Lb libc
39.Sh SYNOPSIS
40.In sys/stat.h
41.In stdlib.h
42.Ft char *
43.Fn devname "dev_t dev" "mode_t type"
44.Ft char *
45.Fn devname_r "dev_t dev" "mode_t type" "char *buf" "int len"
46.Sh DESCRIPTION
47The
48.Fn devname
49function returns a pointer to the name of the block or character
50device in
51.Pa /dev
52with a device number of
53.Fa dev ,
54and a file type matching the one encoded in
55.Fa type
56which must be one of
57.Dv S_IFBLK
58or
59.Dv S_IFCHR .
60To find the right name,
61.Fn devname
62asks the kernel via the
63.Va kern.devname
64sysctl.
65If it is unable to come up with a suitable name,
66it will format the information encapsulated in
67.Fa dev
68and
69.Fa type
70in a human-readable format.
71.Pp
72.Fn devname
73returns the name stored in a static buffer which will be overwritten
74on subsequent calls.
75.Fn devname_r
76takes a buffer and length as argument to avoid this problem.
77.Sh EXAMPLES
78.Bd -literal -compact
79int fd;
80struct stat buf;
81char *name;
82
83 fd = open("/dev/tun");
84 fstat(fd, &buf);
85 printf("devname is /dev/%s\en", devname(buf.st_rdev, S_IFCHR));
86.Ed
87.Sh SEE ALSO
88.Xr stat 2
89.Sh HISTORY
90The
91.Fn devname
92function appeared in
93.Bx 4.4 .