1 /* $NetBSD: strlcat.c,v 1.2 2015/01/22 03:48:07 christos 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 #if !defined(_KERNEL) && !defined(_STANDALONE) 21 #if HAVE_CONFIG_H 22 #include "config.h" 23 #endif 24 25 #include <sys/cdefs.h> 26 #if defined(LIBC_SCCS) && !defined(lint) 27 __RCSID("$NetBSD: strlcat.c,v 1.2 2015/01/22 03:48:07 christos Exp $"); 28 #endif /* LIBC_SCCS and not lint */ 29 30 #ifdef _LIBC 31 #include "namespace.h" 32 #endif 33 #include <sys/types.h> 34 #include <assert.h> 35 #include <string.h> 36 37 #ifdef _LIBC 38 # ifdef __weak_alias 39 __weak_alias(strlcat, _strlcat) 40 # endif 41 #endif 42 43 #else 44 #include <lib/libkern/libkern.h> 45 #endif /* !_KERNEL && !_STANDALONE */ 46 47 #if !HAVE_STRLCAT 48 /* 49 * Appends src to string dst of size siz (unlike strncat, siz is the 50 * full size of dst, not space left). At most siz-1 characters 51 * will be copied. Always NUL terminates (unless siz <= strlen(dst)). 52 * Returns strlen(src) + MIN(siz, strlen(initial dst)). 53 * If retval >= siz, truncation occurred. 54 */ 55 size_t 56 strlcat(char *dst, const char *src, size_t siz) 57 { 58 #if 1 59 char *d = dst; 60 const char *s = src; 61 size_t n = siz; 62 size_t dlen; 63 64 /* Find the end of dst and adjust bytes left but don't go past end */ 65 while (n-- != 0 && *d != '\0') 66 d++; 67 dlen = d - dst; 68 n = siz - dlen; 69 70 if (n == 0) 71 return(dlen + strlen(s)); 72 while (*s != '\0') { 73 if (n != 1) { 74 *d++ = *s; 75 n--; 76 } 77 s++; 78 } 79 *d = '\0'; 80 81 return(dlen + (s - src)); /* count does not include NUL */ 82 #else 83 84 /* 85 * Find length of string in dst (maxing out at siz). 86 */ 87 size_t dlen = strnlen(dst, siz); 88 89 /* 90 * Copy src into any remaining space in dst (truncating if needed). 91 * Note strlcpy(dst, src, 0) returns strlen(src). 92 */ 93 return dlen + strlcpy(dst + dlen, src, siz - dlen); 94 #endif 95 } 96 #endif 97