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.\" @(#)byteorder.3 8.1 (Berkeley) 6/4/93 29.\" 30.Dd March 20, 2005 31.Dt BYTEORDER 3 32.Os 33.Sh NAME 34.Nm htonl , 35.Nm htons , 36.Nm ntohl , 37.Nm ntohs 38.Nd convert values between host and network byte order 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In arpa/inet.h 43.Pp 44or 45.Pp 46.In netinet/in.h 47.Ft uint32_t 48.Fn htonl "uint32_t hostlong" 49.Ft uint16_t 50.Fn htons "uint16_t hostshort" 51.Ft uint32_t 52.Fn ntohl "uint32_t netlong" 53.Ft uint16_t 54.Fn ntohs "uint16_t netshort" 55.Sh DESCRIPTION 56These routines convert 16 and 32 bit quantities between network 57byte order and host byte order. 58On machines which have a byte order which is the same as the network 59order, routines are defined as null macros. 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 gethostbyname 3 , 68.Xr getservent 3 , 69.Xr byteorder 9 70.Sh STANDARDS 71The 72.Nm byteorder 73functions conform to 74.St -p1003.1-2001 . 75.Sh HISTORY 76The 77.Nm byteorder 78functions appeared in 79.Bx 4.2 . 80.Sh BUGS 81On the 82.Tn VAX 83bytes are handled backwards from most everyone else in 84the world. 85This is not expected to be fixed in the near future. 86