minix/lib/nbsd_libc/string/swab.3

93 lines
2.6 KiB
Groff
Raw Normal View History

.\" Copyright (c) 1990, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" from: @(#)swab.3 8.1 (Berkeley) 6/4/93
.\" $NetBSD: swab.3,v 1.15 2010/04/30 03:52:13 jruoho Exp $
.\"
.Dd April 30, 2010
.Dt SWAB 3
.Os
.Sh NAME
.Nm swab
.Nd swap adjacent bytes
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In unistd.h
.Ft void
.Fn swab "const void * restrict src" "void * restrict dst" "ssize_t len"
.Sh DESCRIPTION
The function
.Fn swab
copies
.Fa len
bytes from the location referenced by
.Fa src
to the location referenced by
.Fa dst ,
swapping adjacent bytes.
.Pp
If
.Fa len
is negative or zero,
.Fn swab
does nothing.
If
.Fa len
is odd,
.Fn swab
copies
.Fa len - 1
bytes and the disposition of the last byte is unspecified.
.Sh SEE ALSO
.Xr bzero 3 ,
.Xr memset 3
.Sh STANDARDS
The
.Fn swab
function conforms to
.St -p1003.1-2001 .
.Sh HISTORY
A
.Fn swab
function appeared in
.At v7 .
It was originally documented to be
.Dq useful for carrying binary data between PDP11's and other machines .
.Pp
In
.Nx 6.0
the type of
.Fa len
was changed from
.Vt size_t
to
.Vt ssize_t
for
.Tn POSIX
compliance.