lib/apr_cpystrn.c

/* ====================================================================
 * Copyright (c) 1995-1999 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
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 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
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 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 */
#ifndef WIN32
#include "apr_config.h"
#else
#include "apr_win.h"
#endif

#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

/*
 * Apache's "replacement" for the strncpy() function. We roll our
 * own to implement these specific changes:
 *   (1) strncpy() doesn't always null terminate and we want it to.
 *   (2) strncpy() null fills, which is bogus, esp. when copy 8byte
 *       strings into 8k blocks.
 *   (3) Instead of returning the pointer to the beginning of
 *       the destination string, we return a pointer to the
 *       terminating '\0' to allow us to "check" for truncation
 *
 * apr_cpystrn() follows the same call structure as strncpy().
 */

API_EXPORT(char *) apr_cpystrn(char *dst, const char *src, size_t dst_size)
{

    char *d, *end;

    if (dst_size == 0) {
        return (dst);
    }

    d = dst;
    end = dst + dst_size - 1;

    for (; d < end; ++d, ++src) {
	if (!(*d = *src)) {
	    return (d);
	}
    }

    *d = '\0';	/* always null terminate */

    return (d);
}