1.\" $OpenBSD: link_ntoa.3,v 1.2 2015/09/10 10:14:20 jmc Exp $ 2.\" 3.\" Copyright (c) 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Donn Seeley at BSDI. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. 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.Dd $Mdocdate: September 10 2015 $ 34.Dt LINK_NTOA 3 35.Os 36.Sh NAME 37.Nm link_ntoa 38.Nd elementary address specification routine for link level access 39.Sh SYNOPSIS 40.In sys/types.h 41.In sys/socket.h 42.In net/if_dl.h 43.Ft char * 44.Fn link_ntoa "const struct sockaddr_dl *sdl" 45.Sh DESCRIPTION 46The 47.Fn link_ntoa 48function takes 49a link-level 50address and returns an 51.Tn ASCII 52string representing some of the information present, 53including the link level address itself, and the interface name 54or number, if present. 55This facility is experimental and is 56still subject to change. 57.Sh RETURN VALUES 58.Fn link_ntoa 59always returns a NUL-terminated string. 60.Sh SEE ALSO 61.Xr ifconfig 8 62.Sh HISTORY 63The 64.Fn link_ntoa 65function appeared in 66.Bx 4.3 Reno . 67.Sh BUGS 68The returned values for 69.Fn link_ntoa 70reside in a static memory area. 71.Pp 72If the 73.Fa sdl_len 74field of the link socket address 75.Fa sdl 76is 0, 77.Fn link_ntoa 78will not insert a colon before the interface address bytes. 79