1/* 2 * Copyright (c) 2011 Apple, Inc. All rights reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23 24#include <string.h> 25 26char * 27stpncpy(char * restrict dst, const char * restrict src, size_t maxlen) { 28 const size_t srclen = strnlen(src, maxlen); 29 if (srclen < maxlen) { 30 // The stpncpy() and strncpy() functions copy at most maxlen 31 // characters from src into dst. 32 memcpy(dst, src, srclen); 33 // If src is less than maxlen characters long, the remainder 34 // of dst is filled with '\0' characters. 35 memset(dst+srclen, 0, maxlen-srclen); 36 // The stpcpy() and stpncpy() functions return a pointer to the 37 // terminating '\0' character of dst. 38 return dst+srclen; 39 } else { 40 // The stpncpy() and strncpy() functions copy at most maxlen 41 // characters from src into dst. 42 memcpy(dst, src, maxlen); 43 // If stpncpy() does not terminate dst with a NUL character, it 44 // instead returns a pointer to src[maxlen] (which does not 45 // necessarily refer to a valid memory location.) 46 return dst+maxlen; 47 } 48} 49