/*
 * gendents.cpp: getdents tester.
 *
 * Copyright (C) 1999, 2001, 2003 by Manfred Spraul.
 *	All rights reserved except the rights granted by the GPL.
 *
 * Redistribution of this file is permitted under the terms of the GNU 
 * General Public License (GPL) version 2 or later.
 * $Header: /pub/home/manfred/cvs-tree/getdents/getdents.cpp,v 1.2 2003/03/22 16:01:34 manfred Exp $
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/types.h>
#include <linux/dirent.h>
#include <linux/unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

#define BUFSZ	131072
unsigned char entries[BUFSZ];

#define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3) \
type name(type1 arg1,type2 arg2,type3 arg3) \
{ \
long __res; \
__asm__ volatile ("int $0x80" \
	: "=a" (__res) \
	: "0" (__NR_##name),"b" ((long)(arg1)),"c" ((long)(arg2)), \
		  "d" ((long)(arg3))); \
__syscall_return(type,__res); \
}

_syscall3(int, getdents, uint, fd, struct dirent *, dirp, uint, count);

static void hexdump(unsigned char* array, int len)
{
	int i;
	for(i=0;i<len;i++) {
		if ((i%16) == 0)
			printf("\n%03x:", i);
		if((i%16)==8)
			printf(":");
		printf("%02x ",(unsigned)array[i]); 
	}
	printf("\n");
}

int main(int argc, char **argv)
{
	int fd, retval, bufsz;
	printf("GETDENTS <dir> <offset> [<bufsz>]\n");
	if (argc < 3 || argc > 4)
		return 1;
	fd = open(argv[1],O_RDONLY);
	if (fd < 0) {
		printf("open failed, errno %d.\n", errno);
		return 2;
	}
	if (argc == 4)
		bufsz = atoi(argv[3]);
	 else
		bufsz = BUFSZ;
	lseek(fd, atoi(argv[2]), SEEK_SET);
	for(;;) {
		int offset = 0;

		retval = getdents(fd, (struct dirent *)entries, bufsz);
		printf("retval is %d.\n", retval);
		if (retval <= 0)
			break;
		while (offset < retval) {
			struct dirent *walk = (struct dirent *)(&entries[offset]);
		//	printf("dirent: %lxh.\n", (unsigned long)walk);
		//	printf("dirent->d_ino = %ld.\n", walk->d_ino);
		//	printf("dirent->d_off = %ld.\n", walk->d_off);
		//	printf("dirent->d_reclen = %ld.\n", walk->d_reclen);
			printf("dirent->d_name = '%s'@%ld\n", walk->d_name, walk->d_off);
			offset += walk->d_reclen;
		}
	}
	return 0;
}