openblt

a hobby OS from the late 90s
git clone http://frotz.net/git/openblt.git
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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