1.\" $NetBSD: byteorder.3,v 1.15 2011/05/03 04:07:39 jruoho Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)byteorder.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd May 3, 2011 33.Dt BYTEORDER 3 34.Os 35.Sh NAME 36.Nm htonl , 37.Nm htons , 38.Nm ntohl , 39.Nm ntohs 40.Nd convert values between host and network byte order 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In arpa/inet.h 45.Ft uint32_t 46.Fn htonl "uint32_t host32" 47.Ft uint16_t 48.Fn htons "uint16_t host16" 49.Ft uint32_t 50.Fn ntohl "uint32_t net32" 51.Ft uint16_t 52.Fn ntohs "uint16_t net16" 53.Sh DESCRIPTION 54These routines convert 16 and 32 bit quantities between network 55byte order and host byte order. 56.Pp 57On machines which have a byte order which is the same as the network 58order, these routines are defined as macros that expand to the value of 59their argument. 60.Pp 61These routines are most often used in conjunction with Internet 62addresses and ports as returned by 63.Xr gethostbyname 3 64and 65.Xr getservent 3 . 66.Sh SEE ALSO 67.Xr bswap 3 , 68.Xr gethostbyname 3 , 69.Xr getservent 3 70.Sh STANDARDS 71The described functions conform to 72.St -p1003.1-2001 . 73.Sh HISTORY 74The 75.Nm byteorder 76functions appeared in 77.Bx 4.2 . 78.Sh BUGS 79The `l' and `s' suffixes in the names are not meaningful in machines 80where long integers are not 32 bits. 81