1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" 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.\" $OpenBSD: swab.3,v 1.9 2014/12/12 20:06:13 schwarze Exp $ 29.\" 30.Dd $Mdocdate: December 12 2014 $ 31.Dt SWAB 3 32.Os 33.Sh NAME 34.Nm swab 35.Nd swap adjacent bytes 36.Sh SYNOPSIS 37.In unistd.h 38.Ft void 39.Fo swab 40.Fa "const void *restrict src" 41.Fa "void *restrict dst" 42.Fa "ssize_t len" 43.Fc 44.Sh DESCRIPTION 45The function 46.Fn swab 47copies 48.Fa len 49bytes from the location referenced by 50.Fa src 51to the location referenced by 52.Fa dst , 53swapping adjacent bytes. 54.Pp 55If 56.Fa len 57is zero or less, 58.Nm 59does nothing. 60If it is odd, what happens to the last byte is unspecified. 61If 62.Fa src 63and 64.Fa dst 65overlap, behaviour is undefined. 66.Sh SEE ALSO 67.Xr bzero 3 , 68.Xr memset 3 69.Sh STANDARDS 70The 71.Nm 72function is compliant with the X/Open System Interfaces option of the 73.St -p1003.1-2008 74specification. 75.Sh HISTORY 76The 77.Fn swab 78function first appeared in 79.At v7 . 80