基础知识：
torrent文件信息存储格式：
bencoding是一种以简洁格式指定和组织数据的方法。支持下列类型：字节串、整数、列表和字典。
1 字符串存储格式: <字符串的长度>:<字符串的内容>
例如： 4:abcd 表示abcd, 2:ab 表示ab
2 数字的存储格式: i<整数>e
例如： i32e 表示整数32, i1024e 表示整数1024
3 列表的存储格式： l<子元素>e 其中：子元素可以是字符串，整数，列表和字典，或者是它们的组合体
例如： l4:asdf4:qwere 表示 [ "asdf", "qwer" ]
4 字典的存储格式： d<<key><value><key><value><key><value>...<key><value>>e
其中：key只能是字符串类型，value则可以是字符串，整数，列表和字典，或者是它们的组合体，key和value必须是成对出现的
例如： d3:cow3:moo4:spam4:eggse 表示 { "cow" => "moo", "spam" => "eggs" }
d4:spaml1:a1:bee 表示 { "spam" => [ "a", "b" ] }
d9:publisher3:bob4:spaml1:a1:be5:counti80ee 表示 { "publisher" => "bob", "spam" => [ "a", "b" ], "count" => 80 }
代码：
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using NPOI.OpenXmlFormats.Spreadsheet;
using Newtonsoft.Json; namespace ConsoleApp
{
/// <summary>
/// Summary description for Class1.-change wdq
/// </summary>
public class Class1
{
static void Main(string[] args)
{
if (args.Length != )
{
Console.WriteLine("请指定torrent文件");
return;
}
string filename = args[];
var data = Torrent.DecodeFile(filename);
//Console.WriteLine(JsonConvert.SerializeObject(data, Newtonsoft.Json.Formatting.Indented));
ShowData(data);
} private static void ShowData(ItemBase data)
{
if (data.ItemType == ItemType.Dictionary)
{
foreach (var kv in (data as DictionaryItem).DictionaryData)
{
switch (kv.Value.ItemType)
{
case ItemType.Dictionary:
Console.WriteLine(kv.Key + ":");
ShowData(kv.Value);
break;
case ItemType.List:
Console.WriteLine(kv.Key + ":");
ShowData(kv.Value);
break;
case ItemType.String:
if (kv.Key == "pieces")
{
break;
}
Console.WriteLine(kv.Key + "=" + (kv.Value as StringItem).StringData);
break;
case ItemType.Number:
Console.WriteLine(kv.Key + "=" + (kv.Value as NumberItem).NumberData);
break;
}
}
}
if (data.ItemType == ItemType.List)
{
foreach (var i in (data as ListItem).ListData)
{
switch (i.ItemType)
{
case ItemType.Dictionary:
case ItemType.List:
ShowData(i);
break;
case ItemType.String:
Console.WriteLine((i as StringItem).StringData);
break;
case ItemType.Number:
Console.WriteLine((i as NumberItem).NumberData);
break;
}
}
}
}
} public class Torrent
{
public static ItemBase DecodeFile(string filename)
{
using (var fs = new FileStream(filename, FileMode.Open))
{
using (BinaryReader br = new BinaryReader(fs))
{
return DecodeData(br);
}
}
} private static ItemBase DecodeData(BinaryReader br, Stack<bool> st = null)
{
var flag = br.PeekChar();
List<byte> ls = new List<byte>();
byte b = ;
switch (flag)
{
case 'e':
br.ReadByte();
return null;
case 'l'://列表
br.ReadByte();
var itemLs = new ListItem();
ItemBase i = null;
if (st == null)
{
st = new Stack<bool>();
}
st.Push(true);
do
{
i = DecodeData(br, new Stack<bool>());
if (i != null)
{
itemLs.ListData.Add(i);
}
else
{
st.Pop();
}
} while (st.Count != && br.BaseStream.Position != br.BaseStream.Length); return itemLs;
case 'd'://字典
br.ReadByte();
var itemDic = new DictionaryItem();
var key = DecodeData(br);
while (key != null && br.BaseStream.Position != br.BaseStream.Length)
{
var val = DecodeData(br);
itemDic.DictionaryData[(key as StringItem).StringData] = val;
key = DecodeData(br);
} return itemDic;
case 'i'://数字
br.ReadByte();
b = br.ReadByte();
while (b != 'e')
{
ls.Add(b);
b = br.ReadByte();
}
return new NumberItem(long.Parse(Encoding.UTF8.GetString(ls.ToArray()))) { RawBytes = ls.ToArray() };
default://字符串
b = br.ReadByte();
while (b != ':')
{
ls.Add(b);
b = br.ReadByte();
}
var len = int.Parse(Encoding.UTF8.GetString(ls.ToArray()));
var bufStr = br.ReadBytes(len);
var data = Encoding.UTF8.GetString(bufStr);
return new StringItem(data) { RawBytes = bufStr };
}
}
} public class ItemBase
{
[JsonIgnore]
public ItemType ItemType { get; set; }
[JsonIgnore]
public byte[] RawBytes { get; set; }
} public class StringItem : ItemBase
{
public StringItem(string data)
{
StringData = data;
ItemType = ItemType.String;
}
public string StringData { get; set; }
}
public class NumberItem : ItemBase
{
public NumberItem(long num)
{
NumberData = num;
ItemType = ItemType.Number;
}
public long NumberData { get; set; }
} public class ListItem : ItemBase
{
public ListItem()
{
ItemType = ItemType.List;
}
public List<ItemBase> ListData { get; set; } = new List<ItemBase>();
} public class DictionaryItem : ItemBase
{
public DictionaryItem()
{
ItemType = ItemType.Dictionary;
}
public Dictionary<string, ItemBase> DictionaryData { get; set; } = new Dictionary<string, ItemBase>();
} public enum ItemType
{
String, Number, List, Dictionary
}
}
Github地址:https://github.com/a14907/AConsoleAppForFun.git
效果：
