/*-
 * Copyright (c) 2015 The FreeBSD Foundation
 * All rights reserved.
 *
 * This software was developed by Edward Tomasz Napierala under sponsorship
 * from the FreeBSD Foundation.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

/*
 * Simple test program for playing with different getdents(2) buffer sizes.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/types.h>
#include <err.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>

#define BUF_SIZE 16 * 1024
//#define BUF_SIZE 1724

static void
usage(void)
{

	fprintf(stderr, "usage: dents bufsize [path]\n");
	exit(1);
}

static const char *
type2str(uint8_t type)
{

	switch (type) {
	case DT_REG:
		return("reg");
	case DT_DIR:
		return("dir");
	case DT_FIFO:
		return("fifo");
	case DT_SOCK:
		return("sock");
	case DT_LNK:
		return("lnk");
	case DT_BLK:
		return("blk");
	case DT_CHR:
		return("chr");
	default:
		return("unknown");
	}
}

int
main(int argc, char *argv[])
{
	int fd, off, nread;
	char buf[BUF_SIZE];
	const char *path;
	struct dirent *d;
	size_t bufsize;

	if (argc < 2 || argc > 3)
		usage();

	bufsize = atoi(argv[1]);
	if (bufsize <= 0)
		err(1, "bufsize must be > 0");
	if (bufsize >= sizeof(buf))
		err(1, "bufsize must be < %zd", sizeof(buf));

	if (argc == 3)
		path = argv[2];
	else
		path = ".";

	fd = open(path, O_RDONLY | O_DIRECTORY);
	if (fd == -1)
		err(1, "%s", path);

	printf("fileno		reclen	type	namlen	name\n");
	printf("--------------------------------------------\n");

	for (;;) {
		nread = getdents(fd, buf, bufsize);
		if (nread == -1)
			err(1, "getdents");

		if (nread == 0)
			break;

		printf("\nnread = %d:\n", nread);

		for (off = 0; off < nread; off += d->d_reclen) {
			d = (struct dirent *)(buf + off);
			printf("%-10u	%d	%s	%u	%s\n",
			    d->d_fileno, d->d_reclen, type2str(d->d_type),
			    d->d_namlen, d->d_name);
		}
	}

	return (0);
}