minix/common/lib/libc/string/strncpy.c

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/* $NetBSD: strncpy.c,v 1.3 2007/06/04 18:19:28 christos Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)strncpy.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: strncpy.c,v 1.3 2007/06/04 18:19:28 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#if !defined(_KERNEL) && !defined(_STANDALONE)
#include <assert.h>
#include <string.h>
#else
#include <lib/libkern/libkern.h>
#endif
#ifdef _FORTIFY_SOURCE
#undef strncpy
#endif
/*
* Copy src to dst, truncating or null-padding to always copy n bytes.
* Return dst.
*/
char *
strncpy(char *dst, const char *src, size_t n)
{
_DIAGASSERT(dst != NULL);
_DIAGASSERT(src != NULL);
if (n != 0) {
char *d = dst;
const char *s = src;
do {
if ((*d++ = *s++) == 0) {
/* NUL pad the remaining n-1 bytes */
while (--n != 0)
*d++ = 0;
break;
}
} while (--n != 0);
}
return (dst);
}