1 /* $NetBSD: strlcat.c,v 1.2 2025/02/11 17:48:30 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 #ifdef HAVE_SYS_CDEFS_H 26 #include <sys/cdefs.h> 27 #endif 28 29 #if defined(LIBC_SCCS) && !defined(lint) 30 __RCSID("$NetBSD: strlcat.c,v 1.2 2025/02/11 17:48:30 christos Exp $"); 31 #endif /* LIBC_SCCS and not lint */ 32 33 #ifdef _LIBC 34 #include "namespace.h" 35 #endif 36 #include <sys/types.h> 37 #include <assert.h> 38 #include <string.h> 39 40 #ifdef _LIBC 41 # ifdef __weak_alias 42 __weak_alias(strlcat, _strlcat) 43 # endif 44 #endif 45 46 #else 47 #include <lib/libkern/libkern.h> 48 #endif /* !_KERNEL && !_STANDALONE */ 49 50 #if !HAVE_STRLCAT 51 /* 52 * Appends src to string dst of size siz (unlike strncat, siz is the 53 * full size of dst, not space left). At most siz-1 characters 54 * will be copied. Always NUL terminates (unless siz <= strlen(dst)). 55 * Returns strlen(src) + MIN(siz, strlen(initial dst)). 56 * If retval >= siz, truncation occurred. 57 */ 58 size_t 59 strlcat(char *dst, const char *src, size_t siz) 60 { 61 #if 1 62 char *d = dst; 63 const char *s = src; 64 size_t n = siz; 65 size_t dlen; 66 67 /* Find the end of dst and adjust bytes left but don't go past end */ 68 while (n-- != 0 && *d != '\0') 69 d++; 70 dlen = d - dst; 71 n = siz - dlen; 72 73 if (n == 0) 74 return(dlen + strlen(s)); 75 while (*s != '\0') { 76 if (n != 1) { 77 *d++ = *s; 78 n--; 79 } 80 s++; 81 } 82 *d = '\0'; 83 84 return(dlen + (s - src)); /* count does not include NUL */ 85 #else 86 87 /* 88 * Find length of string in dst (maxing out at siz). 89 */ 90 size_t dlen = strnlen(dst, siz); 91 92 /* 93 * Copy src into any remaining space in dst (truncating if needed). 94 * Note strlcpy(dst, src, 0) returns strlen(src). 95 */ 96 return dlen + strlcpy(dst + dlen, src, siz - dlen); 97 #endif 98 } 99 #endif 100