Commenter et expliquer un code
Bonjour à tous,
j'ai un code écrit en C# mais j'arrive pas à comprendre, SVP, pouvez vous me le commenter , j'ai rien compris :( merciiiiiiiiiiiii d'avance
Code:
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using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Text;
using System.Net.Sockets;
namespace VODWebService
{
enum Verbs
{
WILL = 251,
WONT = 252,
DO = 253,
DONT = 254,
IAC = 255
}
enum Options
{
SGA = 3
}
class TelnetConnection
{
TcpClient tcpSocket;
int TimeOutMs = 100;
public TelnetConnection(string Hostname, int Port)
{
tcpSocket = new TcpClient(Hostname, Port);
}
public string Login(string Username, string Password, int LoginTimeOutMs)
{
int oldTimeOutMs = TimeOutMs;
TimeOutMs = LoginTimeOutMs;
string s = Read();
if (!s.TrimEnd().EndsWith(":"))
throw new Exception("Failed to connect : no login prompt");
WriteLine(Username);
s += Read();
if (!s.TrimEnd().EndsWith(":"))
throw new Exception("Failed to connect : no password prompt");
WriteLine(Password);
s += Read();
TimeOutMs = oldTimeOutMs;
return s;
}
public void WriteLine(string cmd)
{
Write(cmd + "\n");
}
public void Write(string cmd)
{
if (!tcpSocket.Connected) return;
byte[] buf = System.Text.ASCIIEncoding.ASCII.GetBytes(cmd.Replace("\0xFF", "\0xFF\0xFF"));
tcpSocket.GetStream().Write(buf, 0, buf.Length);
}
public string Read()
{
if (!tcpSocket.Connected) return null;
StringBuilder sb = new StringBuilder();
do
{
ParseTelnet(sb);
System.Threading.Thread.Sleep(TimeOutMs);
} while (tcpSocket.Available > 0);
return sb.ToString();
}
public bool IsConnected
{
get { return tcpSocket.Connected; }
}
void ParseTelnet(StringBuilder sb)
{
while (tcpSocket.Available > 0)
{
int input = tcpSocket.GetStream().ReadByte();
switch (input)
{
case -1:
break;
case (int)Verbs.IAC:
// interpret as command
int inputverb = tcpSocket.GetStream().ReadByte();
if (inputverb == -1) break;
switch (inputverb)
{
case (int)Verbs.IAC:
//literal IAC = 255 escaped, so append char 255 to string
sb.Append(inputverb);
break;
case (int)Verbs.DO:
case (int)Verbs.DONT:
case (int)Verbs.WILL:
case (int)Verbs.WONT:
// reply to all commands with "WONT", unless it is SGA (suppres go ahead)
int inputoption = tcpSocket.GetStream().ReadByte();
if (inputoption == -1) break;
tcpSocket.GetStream().WriteByte((byte)Verbs.IAC);
if (inputoption == (int)Options.SGA)
tcpSocket.GetStream().WriteByte(inputverb == (int)Verbs.DO ? (byte)Verbs.WILL : (byte)Verbs.DO);
else
tcpSocket.GetStream().WriteByte(inputverb == (int)Verbs.DO ? (byte)Verbs.WONT : (byte)Verbs.DONT);
tcpSocket.GetStream().WriteByte((byte)inputoption);
break;
default:
break;
}
break;
default:
sb.Append((char)input);
break;
}
}
}
}
} |
