wcsncpy.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#if 0
36#if defined(LIBC_SCCS) && !defined(lint)
37static char sccsid[] = "@(#)strncpy.c	8.1 (Berkeley) 6/4/93";
38#endif /* LIBC_SCCS and not lint */
39#endif
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: stable/11/lib/libc/string/wcsncpy.c 330897 2018-03-14 03:19:51Z eadler $");
42
43#include <wchar.h>
44
45/*
46 * Copy src to dst, truncating or null-padding to always copy n bytes.
47 * Return dst.
48 */
49wchar_t *
50wcsncpy(wchar_t * __restrict dst, const wchar_t * __restrict src, size_t n)
51{
52	if (n != 0) {
53		wchar_t *d = dst;
54		const wchar_t *s = src;
55
56		do {
57			if ((*d++ = *s++) == L'\0') {
58				/* NUL pad the remaining n-1 bytes */
59				while (--n != 0)
60					*d++ = L'\0';
61				break;
62			}
63		} while (--n != 0);
64	}
65	return (dst);
66}
67