xref: /illumos-gate/usr/src/lib/libc/port/gen/strlcat.c (revision 1da57d55)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7257d1b4Sraf  * Common Development and Distribution License (the "License").
6*7257d1b4Sraf  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
21*7257d1b4Sraf 
227c478bd9Sstevel@tonic-gate /*
23*7257d1b4Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
27*7257d1b4Sraf #include "lint.h"
287c478bd9Sstevel@tonic-gate #include <string.h>
297c478bd9Sstevel@tonic-gate #include <sys/types.h>
307c478bd9Sstevel@tonic-gate 
317c478bd9Sstevel@tonic-gate /*
327c478bd9Sstevel@tonic-gate  * Appends src to the dstsize buffer at dst. The append will never
337c478bd9Sstevel@tonic-gate  * overflow the destination buffer and the buffer will always be null
347c478bd9Sstevel@tonic-gate  * terminated. Never reference beyond &dst[dstsize-1] when computing
357c478bd9Sstevel@tonic-gate  * the length of the pre-existing string.
367c478bd9Sstevel@tonic-gate  */
377c478bd9Sstevel@tonic-gate 
387c478bd9Sstevel@tonic-gate size_t
strlcat(char * dst,const char * src,size_t dstsize)397c478bd9Sstevel@tonic-gate strlcat(char *dst, const char *src, size_t dstsize)
407c478bd9Sstevel@tonic-gate {
417c478bd9Sstevel@tonic-gate 	char *df = dst;
427c478bd9Sstevel@tonic-gate 	size_t left = dstsize;
437c478bd9Sstevel@tonic-gate 	size_t l1;
447c478bd9Sstevel@tonic-gate 	size_t l2 = strlen(src);
457c478bd9Sstevel@tonic-gate 	size_t copied;
467c478bd9Sstevel@tonic-gate 
477c478bd9Sstevel@tonic-gate 	while (left-- != 0 && *df != '\0')
487c478bd9Sstevel@tonic-gate 		df++;
497c478bd9Sstevel@tonic-gate 	l1 = df - dst;
507c478bd9Sstevel@tonic-gate 	if (dstsize == l1)
517c478bd9Sstevel@tonic-gate 		return (l1 + l2);
527c478bd9Sstevel@tonic-gate 
537c478bd9Sstevel@tonic-gate 	copied = l1 + l2 >= dstsize ? dstsize - l1 - 1 : l2;
547c478bd9Sstevel@tonic-gate 	(void) memcpy(dst + l1, src, copied);
557c478bd9Sstevel@tonic-gate 	dst[l1+copied] = '\0';
567c478bd9Sstevel@tonic-gate 	return (l1 + l2);
577c478bd9Sstevel@tonic-gate }
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