1 // SPDX-License-Identifier: BSD-3-Clause 2 /* This file is copied from newlib-1.19 */ 3 4 /* $OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $ */ 5 6 /* 7 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 22 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 23 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 24 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 27 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 30 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char *rcsid = 35 "$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <types_ext.h> 39 #include <string_ext.h> 40 /* #include <string.h> */ 41 42 size_t strlen(const char *s); 43 /* 44 * Appends src to string dst of size siz (unlike strncat, siz is the 45 * full size of dst, not space left). At most siz-1 characters 46 * will be copied. Always NUL terminates (unless siz <= strlen(dst)). 47 * Returns strlen(src) + MIN(siz, strlen(initial dst)). 48 * If retval >= siz, truncation occurred. 49 */ 50 size_t strlcat(char *dst, const char *src, size_t siz) 51 { 52 register char *d = dst; 53 register const char *s = src; 54 register size_t n = siz; 55 size_t dlen; 56 57 /* Find the end of dst and adjust bytes left but don't go past end */ 58 while (n-- != 0 && *d != '\0') 59 d++; 60 dlen = d - dst; 61 n = siz - dlen; 62 63 if (n == 0) 64 return dlen + strlen(s); 65 66 while (*s != '\0') { 67 if (n != 1) { 68 *d++ = *s; 69 n--; 70 } 71 s++; 72 } 73 *d = '\0'; 74 75 return dlen + (s - src); /* count does not include NUL */ 76 } 77