Can anybody help me in a ftp program?

[fjlpf]

Hi

I am a beginner of programming. These days, I try to
develop a ftp program. But I find it is harder than I
have thought.
I want to post my code, then concentrate on resolving
the multithread problem and the communication problem
between the client and the server.

Can anybody help me or just join the discussion?

[Peter Koen]

"fjlpf" <an*******@discussions.microsoft.com> wrote in news:054a01c3ac35
$0****************@phx.gbl:

Hi

I am a beginner of programming. These days, I try to
develop a ftp program. But I find it is harder than I
have thought.
I want to post my code, then concentrate on resolving
the multithread problem and the communication problem
between the client and the server.

Can anybody help me or just join the discussion?

Well, start with some palpable question and we will be able to help you...

cheers,
Peter

--
------ooo---OOO---ooo------

Peter Koen - www.kema.at
MCAD CAI/RS CASE/RS IAT

------ooo---OOO---ooo------

[Konrad Neitzel]

Hi "fjlpf",

(Your parents really gave you that name? :) )

"fjlpf" <an*******@discussions.microsoft.com> schrieb im Newsbeitrag
news:05****************************@phx.gbl...

I am a beginner of programming. These days, I try to
develop a ftp program. But I find it is harder than I
have thought.
I want to post my code, then concentrate on resolving
the multithread problem and the communication problem
between the client and the server.

As Peter told you already: Ask a question and maybe we could answer it.

And: Please go to google and search a little. Or simply go to
http://www.codeproject.com/csharp/

There you find a lot of stuff about ftp and c#.

Some small examples are:
FTP Component in C# for .NET:
http://www.codeproject.com/csharp/ftp.asp
FTP client library for C#:
http://www.codeproject.com/csharp/ftplibrary.asp
Application for uploading modified Files to a FTP Server
http://www.codeproject.com/csharp/net_ftp_upload.asp

With kind regards,

Konrad

Here is my code of ftp server. And I just extract the
implement of the function of transfering files.
I know it is very awful, so I am here to asked for your
help.

namespace FtpSrvr
{
public class Form1 : System.Windows.Forms.Form
{
private bool srv = true;
private IPAddress ipAddr;
private IPEndPoint ipEP;
public Socket sock_accpt;//port 20
public Socket sock_daccpt;//port 21
private Thread thrd_accpt;//a thread to accept connection
private Thread thrd_Daccpt;

public int total =0;

..........

[STAThread]
static void Main()
{Application.Run(new Form1()); }
................

private void btStartSrvr_Click(object sender,
System.EventArgs e)
{
this.btStartSrvr.Enabled = false;
ipAddr = IPAddress.Parse("127.0.0.1");
IPEndPoint ipEP1 = new IPEndPoint(ipAddr,20);
sock_accpt = new Socket
(AddressFamily.InterNetwork,SocketType.Stream,Prot ocolType.
Tcp);
sock_accpt.Bind((EndPoint)ipEP1);
sock_accpt.Listen(5);
//
IPEndPoint ipEP2 = new IPEndPoint(ipAddr,21);
sock_daccpt = new Socket
(AddressFamily.InterNetwork,SocketType.Stream,Prot ocolType.
Tcp);
sock_daccpt.Bind((EndPoint)ipEP2);
sock_daccpt.Listen(5);

//create new thread to accept connection
thrd_Accpt = new Thread(new ThreadStart(this.Thrd_Accpt));
thrd_Accpt.Start();

}
private void Thrd_Accpt()
{
while(srv)//
{ Socket newClient = sock_accpt.Accept();

ThreadStartCommand c = new ThreadStartCommand
(newClient,this.sock_daccpt);

Thread thrd = new Thread(new ThreadStart(c.Thrd_Command));
thrd.Start();
}
}

internal class ThreadStartCommand
{
private Socket _sock;//store the socket created by accept()
private Form1 _form;

public ThreadStartCommand(Socket sock, Form1 form
{ _sock = sock;
_form = form;
}

//this function aims to retrevie command
public void Thrd_Command()
{
_sock.SetSocketOption
(SocketOptionLevel.Socket,SocketOptionName.SendTim eout,5000
);

byte[] b= System.Text.Encoding.ASCII.GetBytes("welcome to
my ftp server");

try
{
_sock.Send(b,0,b.Length,SocketFlags.None);
}
catch(SocketException ex)
{
System.Diagnostics.Debug.Write("error to send welcome
message" );
return;
}
_sock.SetSocketOption
(SocketOptionLevel.Socket,SocketOptionName.Receive Timeout,2
0000);

byte[] buffer = new byte[1024];
int rcv ;
while(true)
{
try
{
rcv = _sock.Receive(buffer,0,1024,SocketFlags.None);
}
catch(SocketException ex)
{
/*if the client doesn't send command within 20 seconds,the
socket will close.*/

_sock.Close();
return
}
}

string s = System.Text.Encoding.ASCII.GetString
(buffer,0,rcv);
s = s.ToLower();
int i = s.IndexOf(" ");
string comCode = s.Substring(0,i);
string para = s.Substring(i+1,rcv-1-i);
AnalyseCommand(comCode,para);
byte[] buffer = ASCII.GetBytes("120 new port allocated");
_sock.Send(buffer,0,buffer.Length,SocketFlags.None );
}
}

public void AnalyseCommand(string comCode, string para)
{
switch(comCode)
{
case "retr":
{
lock(this._form.sock_daccpt)//
{if(this._form.total<4)
this._form.total++;//restrict total connection of Port 21
else
{byte[] buf = System.Text.Encoding.ASCII.GetBytes("sorry,
overload");
this._sock.Send(buf,0,buf.Length,SocketFlags.None) ;
return;
}
}
Thread thrd = new Thread(new ThreadStart
(this.ThrdSndFile));

thrd.Start();// thread to transfer file to client
}
break;
}
case "":...

case "":...
}
}

public void ThrdSndFile(Socket accpt, string para)
{
Socket dataclient = this._form.sock_daccpt.Accept();
FileStream fs;
try
{
fs = new FileStream
(@para,FileMode.Open,FileAccess.Read,FileShare.Rea d);
}
catch(IOException ex)
{dataclient.Close();
return;
}

dataclient.SetSocketOption
(SocketOptionLevel.Socket,SocketOptionName.SendTim eout,5000
0);
int rd = 1;

while(rd!=0)
{
//Question:if the client socket collapse, what happen to
//socket of server, does it still push data to TCP's buffer
byte[] buffer = new byte[1024];
rd = fs.Read(buffer,0,1024);

try
{_sock.Send(buffer,0,rd,SocketFlags.None);
}
catch(SocketException ex)
{
lock(this._form._sock_daccpt)
{ this._form.total--;
}
_sock.Close();
return;
}
}
}

_sock.Close();
}
}
}

[fjlpf]

:)
konrad,
my parents' taste isn't awful like me.

with kind regards

[Konrad Neitzel]

Hi!

"fjlpf" <an*******@discussions.microsoft.com> schrieb im Newsbeitrag
news:05****************************@phx.gbl...

:)
konrad,
my parents' taste isn't awful like me.

Then everything is ok for me. I hope, my links helped a little.

With kind regards,

Konrad