xref: /onnv-gate/usr/src/lib/libc/port/gen/strlcat.c (revision 6812:febeba71273d)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*6812Sraf  * Common Development and Distribution License (the "License").
6*6812Sraf  * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate  *
80Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate  * See the License for the specific language governing permissions
110Sstevel@tonic-gate  * and limitations under the License.
120Sstevel@tonic-gate  *
130Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate  *
190Sstevel@tonic-gate  * CDDL HEADER END
200Sstevel@tonic-gate  */
21*6812Sraf 
220Sstevel@tonic-gate /*
23*6812Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
240Sstevel@tonic-gate  * Use is subject to license terms.
250Sstevel@tonic-gate  */
260Sstevel@tonic-gate 
270Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
280Sstevel@tonic-gate 
29*6812Sraf #include "lint.h"
300Sstevel@tonic-gate #include <string.h>
310Sstevel@tonic-gate #include <sys/types.h>
320Sstevel@tonic-gate 
330Sstevel@tonic-gate /*
340Sstevel@tonic-gate  * Appends src to the dstsize buffer at dst. The append will never
350Sstevel@tonic-gate  * overflow the destination buffer and the buffer will always be null
360Sstevel@tonic-gate  * terminated. Never reference beyond &dst[dstsize-1] when computing
370Sstevel@tonic-gate  * the length of the pre-existing string.
380Sstevel@tonic-gate  */
390Sstevel@tonic-gate 
400Sstevel@tonic-gate size_t
strlcat(char * dst,const char * src,size_t dstsize)410Sstevel@tonic-gate strlcat(char *dst, const char *src, size_t dstsize)
420Sstevel@tonic-gate {
430Sstevel@tonic-gate 	char *df = dst;
440Sstevel@tonic-gate 	size_t left = dstsize;
450Sstevel@tonic-gate 	size_t l1;
460Sstevel@tonic-gate 	size_t l2 = strlen(src);
470Sstevel@tonic-gate 	size_t copied;
480Sstevel@tonic-gate 
490Sstevel@tonic-gate 	while (left-- != 0 && *df != '\0')
500Sstevel@tonic-gate 		df++;
510Sstevel@tonic-gate 	l1 = df - dst;
520Sstevel@tonic-gate 	if (dstsize == l1)
530Sstevel@tonic-gate 		return (l1 + l2);
540Sstevel@tonic-gate 
550Sstevel@tonic-gate 	copied = l1 + l2 >= dstsize ? dstsize - l1 - 1 : l2;
560Sstevel@tonic-gate 	(void) memcpy(dst + l1, src, copied);
570Sstevel@tonic-gate 	dst[l1+copied] = '\0';
580Sstevel@tonic-gate 	return (l1 + l2);
590Sstevel@tonic-gate }
60