strndup.c

/*	$OpenBSD: strndup.c,v 1.3 2019/01/25 00:19:25 millert Exp $	*/
/*	$OpenBSD: strnlen.c,v 1.9 2019/01/25 00:19:25 millert Exp $	*/

/*
 * Copyright (c) 2010 Todd C. Miller <millert@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stddef.h>
#include <stdlib.h>
#include <string.h>

#include "config.h"

#ifndef HAVE_STRNDUP

static size_t
strnlen(const char *str, size_t maxlen)
{
	const char *cp;

	for (cp = str; maxlen != 0 && *cp != '\0'; cp++, maxlen--)
		;

	return (size_t)(cp - str);
}

char *
strndup(const char *str, size_t maxlen)
{
	char *copy;
	size_t len;

	len = strnlen(str, maxlen);
	copy = malloc(len + 1);
	if (copy != NULL) {
		(void)memcpy(copy, str, len);
		copy[len] = '\0';
	}

	return copy;
}

#endif /* !HAVE_STRNDUP */