xref: /freebsd/lib/libc/string/stpncpy.c (revision 69099ba2ec8b01fe51a5c69b98990cde406c5ab8)
169099ba2SDavid Schultz /*-
269099ba2SDavid Schultz  * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
369099ba2SDavid Schultz  * All rights reserved.
469099ba2SDavid Schultz  *
569099ba2SDavid Schultz  * Redistribution and use in source and binary forms, with or without
669099ba2SDavid Schultz  * modification, are permitted provided that the following conditions
769099ba2SDavid Schultz  * are met:
869099ba2SDavid Schultz  * 1. Redistributions of source code must retain the above copyright
969099ba2SDavid Schultz  *    notice, this list of conditions and the following disclaimer.
1069099ba2SDavid Schultz  * 2. Redistributions in binary form must reproduce the above copyright
1169099ba2SDavid Schultz  *    notice, this list of conditions and the following disclaimer in the
1269099ba2SDavid Schultz  *    documentation and/or other materials provided with the distribution.
1369099ba2SDavid Schultz  *
1469099ba2SDavid Schultz  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1569099ba2SDavid Schultz  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1669099ba2SDavid Schultz  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1769099ba2SDavid Schultz  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1869099ba2SDavid Schultz  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1969099ba2SDavid Schultz  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2069099ba2SDavid Schultz  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2169099ba2SDavid Schultz  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2269099ba2SDavid Schultz  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2369099ba2SDavid Schultz  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2469099ba2SDavid Schultz  * SUCH DAMAGE.
2569099ba2SDavid Schultz  */
2669099ba2SDavid Schultz 
2769099ba2SDavid Schultz #include <sys/cdefs.h>
2869099ba2SDavid Schultz __FBSDID("$FreeBSD$");
2969099ba2SDavid Schultz 
3069099ba2SDavid Schultz #include <string.h>
3169099ba2SDavid Schultz 
3269099ba2SDavid Schultz char *
3369099ba2SDavid Schultz stpncpy(char * __restrict dst, const char * __restrict src, size_t n)
3469099ba2SDavid Schultz {
3569099ba2SDavid Schultz 
3669099ba2SDavid Schultz 	for (; n--; dst++, src++) {
3769099ba2SDavid Schultz 		if (!(*dst = *src)) {
3869099ba2SDavid Schultz 			char *ret = dst;
3969099ba2SDavid Schultz 			while (n--)
4069099ba2SDavid Schultz 				*++dst = '\0';
4169099ba2SDavid Schultz 			return (ret);
4269099ba2SDavid Schultz 		}
4369099ba2SDavid Schultz 	}
4469099ba2SDavid Schultz 	return (dst);
4569099ba2SDavid Schultz }
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