xref: /openbsd-src/lib/libc/string/swab.c (revision 0a2869cb84f502f2092fa3251feedea723042c8f)
1*0a2869cbStedu /*	$OpenBSD: swab.c,v 1.9 2014/12/11 23:05:38 tedu Exp $ */
2df930be7Sderaadt /*
3*0a2869cbStedu  * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
4df930be7Sderaadt  *
5*0a2869cbStedu  * Permission to use, copy, modify, and distribute this software for any
6*0a2869cbStedu  * purpose with or without fee is hereby granted, provided that the above
7*0a2869cbStedu  * copyright notice and this permission notice appear in all copies.
8df930be7Sderaadt  *
9*0a2869cbStedu  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10*0a2869cbStedu  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11*0a2869cbStedu  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12*0a2869cbStedu  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13*0a2869cbStedu  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14*0a2869cbStedu  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15*0a2869cbStedu  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16df930be7Sderaadt  */
17c1f33f96Sderaadt #include <unistd.h>
18df930be7Sderaadt 
19df930be7Sderaadt void
swab(const void * __restrict from,void * __restrict to,ssize_t len)20*0a2869cbStedu swab(const void *__restrict from, void *__restrict to, ssize_t len)
21df930be7Sderaadt {
22*0a2869cbStedu 	const unsigned char *src = from;
23*0a2869cbStedu 	unsigned char *dst = to;
24*0a2869cbStedu 	unsigned char t0, t1;
25df930be7Sderaadt 
26*0a2869cbStedu 	while (len > 1) {
27*0a2869cbStedu 		t0 = src[0];
28*0a2869cbStedu 		t1 = src[1];
29*0a2869cbStedu 		dst[0] = t1;
30*0a2869cbStedu 		dst[1] = t0;
31*0a2869cbStedu 		src += 2;
32*0a2869cbStedu 		dst += 2;
33*0a2869cbStedu 		len -= 2;
34df930be7Sderaadt 	}
35df930be7Sderaadt }
36