1/* $NetBSD: strlcat.c,v 1.4 2013/01/23 07:57:27 matt Exp $ */ 2/* $OpenBSD: strlcat.c,v 1.10 2003/04/12 21:56:39 millert Exp $ */ 3 4/* 5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL 12 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 13 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE 14 * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 16 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 17 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20#include "config.h" 21 22#if defined(LIBC_SCCS) && !defined(lint) 23__RCSID("$NetBSD: strlcat.c,v 1.4 2013/01/23 07:57:27 matt Exp $"); 24#endif /* LIBC_SCCS and not lint */ 25 26#include <sys/types.h> 27#include <assert.h> 28#include <string.h> 29 30#ifdef _LIBC 31# ifdef __weak_alias 32__weak_alias(strlcat, _strlcat) 33# endif 34#endif 35 36#if !HAVE_STRLCAT 37/* 38 * Appends src to string dst of size siz (unlike strncat, siz is the 39 * full size of dst, not space left). At most siz-1 characters 40 * will be copied. Always NUL terminates (unless siz <= strlen(dst)). 41 * Returns strlen(src) + MIN(siz, strlen(initial dst)). 42 * If retval >= siz, truncation occurred. 43 */ 44size_t 45strlcat(char *dst, const char *src, size_t siz) 46{ 47#if 1 48 char *d = dst; 49 const char *s = src; 50 size_t n = siz; 51 size_t dlen; 52 53 _DIAGASSERT(dst != NULL); 54 _DIAGASSERT(src != NULL); 55 56 /* Find the end of dst and adjust bytes left but don't go past end */ 57 while (n-- != 0 && *d != '\0') 58 d++; 59 dlen = d - dst; 60 n = siz - dlen; 61 62 if (n == 0) 63 return(dlen + strlen(s)); 64 while (*s != '\0') { 65 if (n != 1) { 66 *d++ = *s; 67 n--; 68 } 69 s++; 70 } 71 *d = '\0'; 72 73 return(dlen + (s - src)); /* count does not include NUL */ 74#else 75 _DIAGASSERT(dst != NULL); 76 _DIAGASSERT(src != NULL); 77 78 /* 79 * Find length of string in dst (maxing out at siz). 80 */ 81 size_t dlen = strnlen(dst, siz); 82 83 /* 84 * Copy src into any remaining space in dst (truncating if needed). 85 * Note strlcpy(dst, src, 0) returns strlen(src). 86 */ 87 return dlen + strlcpy(dst + dlen, src, siz - dlen); 88#endif 89} 90#endif 91