1 /* $OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 * 18 * $FreeBSD: head/lib/libc/string/strlcat.c 189133 2009-02-28 05:15:02Z das $ 19 */ 20 21 #include <sys/types.h> 22 #include <string.h> 23 24 /* 25 * Appends src to string dst of size siz (unlike strncat, siz is the 26 * full size of dst, not space left). At most siz-1 characters 27 * will be copied. Always NUL terminates (unless siz <= strlen(dst)). 28 * Returns strlen(src) + MIN(siz, strlen(initial dst)). 29 * If retval >= siz, truncation occurred. 30 */ 31 size_t 32 strlcat(char * __restrict dst, const char * __restrict src, size_t siz) 33 { 34 char *d = dst; 35 const char *s = src; 36 size_t n = siz; 37 size_t dlen; 38 39 /* Find the end of dst and adjust bytes left but don't go past end */ 40 while (n-- != 0 && *d != '\0') 41 d++; 42 dlen = d - dst; 43 n = siz - dlen; 44 45 if (n == 0) 46 return(dlen + strlen(s)); 47 while (*s != '\0') { 48 if (n != 1) { 49 *d++ = *s; 50 n--; 51 } 52 s++; 53 } 54 *d = '\0'; 55 56 return(dlen + (s - src)); /* count does not include NUL */ 57 } 58