/*
 * buf-sub.c -- simple string buffer for C
 *
 * Copyright (c) 2019-2021 David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or 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 <assert.h>
#include <stdlib.h>
#include <string.h>

#include "buf.h"

int
buf_sub(struct buf *b, const struct buf *src, size_t pos, size_t count)
{
	assert(b);
	assert(src);
	assert(pos <= src->length);

	if (count >= src->length)
		count = src->length - pos;
	if (!(b->data = BUF_MALLOC(count + 1)))
		return -1;

	strncpy(b->data, &src->data[pos], count);
	b->length = count;
	b->capacity = count;
	b->data[b->length] = 0;

	return 0;
}