1.\" Copyright (c) 1983, 1991, 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.\" @(#)byteorder.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/net/byteorder.3,v 1.3.2.4 2001/12/14 18:33:55 ru Exp $ 34.\" $DragonFly: src/lib/libc/net/byteorder.3,v 1.3 2004/09/15 15:04:31 joerg Exp $ 35.\" 36.Dd June 4, 1993 37.Dt BYTEORDER 3 38.Os 39.Sh NAME 40.Nm htonl , 41.Nm htons , 42.Nm ntohl , 43.Nm ntohs 44.Nd convert values between host and network byte order 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.In arpa/inet.h 49.Ft uint32_t 50.Fn htonl "uint32_t hostlong" 51.Ft uint16_t 52.Fn htons "uint16_t hostshort" 53.Ft uint32_t 54.Fn ntohl "uint32_t netlong" 55.Ft uint16_t 56.Fn ntohs "uint16_t netshort" 57.Sh DESCRIPTION 58These routines convert 16 and 32 bit quantities between network 59byte order and host byte order. 60On machines which have a byte order which is the same as the network 61order, routines are defined as null macros. 62.Pp 63These routines are most often used in conjunction with Internet 64addresses and ports as returned by 65.Xr gethostbyname 3 66and 67.Xr getservent 3 . 68.Sh SEE ALSO 69.Xr gethostbyname 3 , 70.Xr getservent 3 71.Sh HISTORY 72The 73.Nm byteorder 74functions appeared in 75.Bx 4.2 . 76.Sh BUGS 77On the 78.Tn VAX 79bytes are handled backwards from most everyone else in 80the world. This is not expected to be fixed in the near future. 81