strncpy.c revision 102281
11541Srgrimes/*- 21541Srgrimes * Copyright (c) 1990, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * This code is derived from software contributed to Berkeley by 61541Srgrimes * Chris Torek. 71541Srgrimes * 81541Srgrimes * Redistribution and use in source and binary forms, with or without 91541Srgrimes * modification, are permitted provided that the following conditions 101541Srgrimes * are met: 111541Srgrimes * 1. Redistributions of source code must retain the above copyright 121541Srgrimes * notice, this list of conditions and the following disclaimer. 131541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141541Srgrimes * notice, this list of conditions and the following disclaimer in the 151541Srgrimes * documentation and/or other materials provided with the distribution. 161541Srgrimes * 3. All advertising materials mentioning features or use of this software 171541Srgrimes * must display the following acknowledgement: 181541Srgrimes * This product includes software developed by the University of 191541Srgrimes * California, Berkeley and its contributors. 201541Srgrimes * 4. Neither the name of the University nor the names of its contributors 211541Srgrimes * may be used to endorse or promote products derived from this software 221541Srgrimes * without specific prior written permission. 231541Srgrimes * 241541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341541Srgrimes * SUCH DAMAGE. 351817Sdg * 3650477Speter * $FreeBSD: head/sys/libkern/strncpy.c 102281 2002-08-22 20:08:07Z jhb $ 371541Srgrimes */ 381541Srgrimes 39102281Sjhb#include <sys/libkern.h> 401541Srgrimes 411541Srgrimes/* 421541Srgrimes * Copy src to dst, truncating or null-padding to always copy n bytes. 431541Srgrimes * Return dst. 441541Srgrimes */ 451541Srgrimeschar * 461541Srgrimesstrncpy(dst, src, n) 471541Srgrimes char *dst; 481541Srgrimes const char *src; 491541Srgrimes register size_t n; 501541Srgrimes{ 511541Srgrimes if (n != 0) { 521541Srgrimes register char *d = dst; 531541Srgrimes register const char *s = src; 541541Srgrimes 551541Srgrimes do { 561541Srgrimes if ((*d++ = *s++) == 0) { 571541Srgrimes /* NUL pad the remaining n-1 bytes */ 581541Srgrimes while (--n != 0) 591541Srgrimes *d++ = 0; 601541Srgrimes break; 611541Srgrimes } 621541Srgrimes } while (--n != 0); 631541Srgrimes } 641541Srgrimes return (dst); 651541Srgrimes} 66