strlcat.c (2363B)
1 /* $Id: //depot/blt/lib/libc/strlcat.c#1 $ */ 2 /* $OpenBSD: strlcat.c,v 1.1 1998/07/01 01:29:45 millert Exp $ */ 3 4 /* 5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 21 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 22 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 24 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 25 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 26 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 27 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 28 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <string.h> 32 33 /* 34 * Appends src to string dst of size siz (unlike strncat, siz is the 35 * full size of dst, not space left). At most siz-1 characters 36 * will be copied. Always NUL terminates (unless siz == 0). 37 * Returns strlen(src); if retval >= siz, truncation occurred. 38 */ 39 size_t strlcat(dst, src, siz) 40 char *dst; 41 const char *src; 42 size_t siz; 43 { 44 register char *d = dst; 45 register const char *s = src; 46 register size_t n = siz; 47 size_t dlen; 48 49 /* Find the end of dst and adjust bytes left */ 50 while (*d != '\0' && n != 0) 51 d++; 52 dlen = d - dst; 53 n -= dlen; 54 55 if (n == 0) 56 return(dlen + strlen(s)); 57 while (*s != '\0') { 58 if (n != 1) { 59 *d++ = *s; 60 n--; 61 } 62 s++; 63 } 64 *d = '\0'; 65 66 return(dlen + (s - src)); /* count does not include NUL */ 67 } 68