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. 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.Dd March 20, 2005 29.Dt BYTEORDER 3 30.Os 31.Sh NAME 32.Nm htonl , 33.Nm htons , 34.Nm ntohl , 35.Nm ntohs 36.Nd convert values between host and network byte order 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In arpa/inet.h 41.Pp 42or 43.Pp 44.In netinet/in.h 45.Ft uint32_t 46.Fn htonl "uint32_t hostlong" 47.Ft uint16_t 48.Fn htons "uint16_t hostshort" 49.Ft uint32_t 50.Fn ntohl "uint32_t netlong" 51.Ft uint16_t 52.Fn ntohs "uint16_t netshort" 53.Sh DESCRIPTION 54These routines convert 16 and 32 bit quantities between network 55byte order and host byte order. 56On machines which have a byte order which is the same as the network 57order, routines are defined as null macros. 58.Pp 59These routines are most often used in conjunction with Internet 60addresses and ports as returned by 61.Xr gethostbyname 3 62and 63.Xr getservent 3 . 64.Sh SEE ALSO 65.Xr gethostbyname 3 , 66.Xr getservent 3 , 67.Xr byteorder 9 68.Sh STANDARDS 69The 70.Nm byteorder 71functions conform to 72.St -p1003.1-2001 . 73.Sh HISTORY 74The 75.Nm byteorder 76functions appeared in 77.Bx 4.2 . 78.Sh BUGS 79On the 80.Tn VAX 81bytes are handled backwards from most everyone else in 82the world. 83This is not expected to be fixed in the near future. 84