1/* $OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $ */ 2 3/* 4 * Copyright (c) 1998, 2003-2005 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 19#include <config.h> 20 21#include <sys/types.h> 22#include <string.h> 23 24#include "missing.h" 25 26/* 27 * Appends src to string dst of size siz (unlike strncat, siz is the 28 * full size of dst, not space left). At most siz-1 characters 29 * will be copied. Always NUL terminates (unless siz <= strlen(dst)). 30 * Returns strlen(src) + MIN(siz, strlen(initial dst)). 31 * If retval >= siz, truncation occurred. 32 */ 33size_t 34strlcat(dst, src, siz) 35 char *dst; 36 const char *src; 37 size_t siz; 38{ 39 char *d = dst; 40 const char *s = src; 41 size_t n = siz; 42 size_t dlen; 43 44 /* Find the end of dst and adjust bytes left but don't go past end */ 45 while (n-- != 0 && *d != '\0') 46 d++; 47 dlen = d - dst; 48 n = siz - dlen; 49 50 if (n == 0) 51 return dlen + strlen(s); 52 while (*s != '\0') { 53 if (n != 1) { 54 *d++ = *s; 55 n--; 56 } 57 s++; 58 } 59 *d = '\0'; 60 61 return dlen + (s - src); /* count does not include NUL */ 62} 63