1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)strncpy.c 8.1 (Berkeley) 6/4/93 33 * $FreeBSD: src/lib/libc/string/strncpy.c,v 1.7 2007/01/09 00:28:12 imp Exp $ 34 * $DragonFly: src/lib/libc/string/strncpy.c,v 1.4 2005/09/18 16:32:34 asmodai Exp $ 35 */ 36 37 #include <string.h> 38 39 /* 40 * Copy src to dst, truncating or null-padding to always copy n bytes. 41 * Return dst. 42 */ 43 char * 44 strncpy(char * __restrict dst, const char * __restrict src, size_t n) 45 { 46 if (n != 0) { 47 char *d = dst; 48 const char *s = src; 49 50 do { 51 if ((*d++ = *s++) == 0) { 52 /* NUL pad the remaining n-1 bytes */ 53 while (--n != 0) 54 *d++ = 0; 55 break; 56 } 57 } while (--n != 0); 58 } 59 return (dst); 60 } 61