ftplib.cs

/* Copyright (c) 2006, J.P. Trosclair
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted 
 * provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice, this list of conditions and 
 *		the following disclaimer.
 *  * 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
 * 
 * Based on FTPFactory.cs code, pretty much a complete re-write with FTPFactory.cs
 * as a reference.
 * 
 ***********************
 * Authors of this code:
 ***********************
 * J.P. Trosclair    (jptrosclair@judelawfirm.com)
 * Filipe Madureira  (filipe_madureira@hotmail.com) 
 * Carlo M. Andreoli (cmandreoli@numericaprogetti.it)
 * Sloan Holliday    (sloan@ipass.net)
 * 
 *********************** 
 * FTPFactory.cs was written by Jaimon Mathew (jaimonmathew@rediffmail.com)
 * and modified by Dan Rolander (Dan.Rolander@marriott.com).
 *	http://www.csharphelp.com/archives/archive9.html
 ***********************
 * 
 * ** DO NOT ** contact the authors of FTPFactory.cs about problems with this code. It
 * is not their responsibility. Only contact people listed as authors of THIS CODE.
 * 
 *  Any bug fixes or additions to the code will be properly credited to the author.
 * 
 *  BUGS: There probably are plenty. If you fix one, please email me with info
 *   about the bug and the fix, code is welcome.
 * 
 * All calls to the ftplib functions should be:
 * 
 * try 
 * { 
 *		// ftplib function call
 * } 
 * catch(Exception ex) 
 * {
 *		// error handeler
 * }
 * 
 * If you add to the code please make use of OpenDataSocket(), CloseDataSocket(), and
 * ReadResponse() appropriately. See the comments above each for info about using them.
 * 
 * The Fail() function terminates the entire connection. Only call it on critical errors.
 * Non critical errors should NOT close the connection.
 * All errors should throw an exception of type Exception with the response string from
 * the server as the message.
 * 
 * See the simple ftp client for examples on using this class
 */

//#define FTP_DEBUG   

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections;

namespace FTPLib
{
	public class FTP
	{
		#region Public Variables

		/// <summary>
		/// IP address or hostname to connect to
		/// </summary>
		public string server;
		/// <summary>
		/// Username to login as
		/// </summary>
		public string user;
		/// <summary>
		/// Password for account
		/// </summary>
		public string pass;
		/// <summary>
		/// Port number the FTP server is listening on
		/// </summary>
		public int port;
		/// <summary>
		/// The timeout (miliseconds) for waiting on data to arrive
		/// </summary>
		public int timeout;
		
		#endregion

		#region Private Variables
		
		private string messages; // server messages
		private string responseStr; // server response if the user wants it.
		private bool passive_mode;		// #######################################
		private long bytes_total; // upload/download info if the user wants it.
		private long file_size; // gets set when an upload or download takes place
		private Socket main_sock;
		private IPEndPoint main_ipEndPoint;
		private Socket listening_sock;
		private Socket data_sock;
		private IPEndPoint data_ipEndPoint;
		private FileStream file;
		private int response;
		private string bucket;
		
		#endregion
		
		#region Constructors
		/// <summary>
		/// Constructor
		/// </summary>
		public FTP()
		{
			server = null;
			user = null;
			pass = null;
			port = 21;
			passive_mode = true;		// #######################################
			main_sock = null;
			main_ipEndPoint = null;
			listening_sock = null;
			data_sock = null;
			data_ipEndPoint = null;
			file = null;
			bucket = "";
			bytes_total = 0;
			timeout = 10000;	// 10 seconds
			messages = "";
		}
		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="server">Server to connect to</param>
		/// <param name="user">Account to login as</param>
		/// <param name="pass">Account password</param>
		public FTP(string server, string user, string pass)
		{
			this.server = server;
			this.user = user;
			this.pass = pass;
			port = 21;
			passive_mode = true;		// #######################################
			main_sock = null;
			main_ipEndPoint = null;
			listening_sock = null;
			data_sock = null;
			data_ipEndPoint = null;
			file = null;
			bucket = "";
			bytes_total = 0;
			timeout = 10000;	// 10 seconds
			messages = "";
		}
		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="server">Server to connect to</param>
		/// <param name="port">Port server is listening on</param>
		/// <param name="user">Account to login as</param>
		/// <param name="pass">Account password</param>
		public FTP(string server, int port, string user, string pass)
		{
			this.server = server;
			this.user = user;
			this.pass = pass;
			this.port = port;
			passive_mode = true;		// #######################################
			main_sock = null;
			main_ipEndPoint = null;
			listening_sock = null;
			data_sock = null;
			data_ipEndPoint = null;
			file = null;
			bucket = "";
			bytes_total = 0;
			timeout = 10000;	// 10 seconds
			messages = "";
		}

		#endregion

		/// <summary>
		/// Connection status to the server
		/// </summary>
		public bool IsConnected
		{
			get
			{
				if (main_sock != null)
					return main_sock.Connected;
				return false;
			}
		}
		/// <summary>
		/// Returns true if the message buffer has data in it
		/// </summary>
		public bool MessagesAvailable
		{
			get
			{
				if(messages.Length > 0)
					return true;
				return false;
			}
		}
		/// <summary>
		/// Server messages if any, buffer is cleared after you access this property
		/// </summary>
		public string Messages
		{
			get
			{
				string tmp = messages;
				messages = "";
				return tmp;
			}
		}
		/// <summary>
		/// The response string from the last issued command
		/// </summary>
		public string ResponseString
		{
			get
			{
				return responseStr;
			}
		}
		/// <summary>
		/// The total number of bytes sent/recieved in a transfer
		/// </summary>
		public long BytesTotal		// #######################################
		{
			get
			{
				return bytes_total;
			}
		}
		/// <summary>
		/// The size of the file being downloaded/uploaded (Can possibly be 0 if no size is available)
		/// </summary>
		public long FileSize		// #######################################
		{
			get
			{
				return file_size;
			}
		}
		/// <summary>
		/// True:  Passive mode [default]
		/// False: Active Mode
		/// </summary>
		public bool PassiveMode		// #######################################
		{
			get
			{
				return passive_mode;
			}
			set
			{
				passive_mode = value;
			}
		}


		private void Fail()
		{
			Disconnect();
			throw new Exception(responseStr);
		}


		private void SetBinaryMode(bool mode)
		{
			if (mode)
				SendCommand("TYPE I");
			else
				SendCommand("TYPE A");

			ReadResponse();
			if (response != 200)
				Fail();
		}


		private void SendCommand(string command)
		{
			Byte[] cmd = Encoding.ASCII.GetBytes((command + "\r\n").ToCharArray());

#if (FTP_DEBUG)
			if (command.Length > 3 && command.Substring(0, 4) == "PASS")
				Console.WriteLine("\rPASS xxx");
			else
				Console.WriteLine("\r" + command);
#endif

			main_sock.Send(cmd, cmd.Length, 0);
		}


		private void FillBucket()
		{
			Byte[] bytes = new Byte[512];
			long bytesgot;
			int msecs_passed = 0;		// #######################################

			while(main_sock.Available < 1)
			{
				System.Threading.Thread.Sleep(50);
				msecs_passed += 50;
				// this code is just a fail safe option 
				// so the code doesn't hang if there is 
				// no data comming.
				if (msecs_passed > timeout)
				{
					Disconnect();
					throw new Exception("Timed out waiting on server to respond.");	
				}
			}

			while(main_sock.Available > 0)
			{
				bytesgot = main_sock.Receive(bytes, 512, 0);
				bucket += Encoding.ASCII.GetString(bytes, 0, (int)bytesgot);
				// this may not be needed, gives any more data that hasn't arrived
				// just yet a small chance to get there.
				System.Threading.Thread.Sleep(50);
			}
		}


		private string GetLineFromBucket()
		{
			int i;
			string buf = "";

			if ((i = bucket.IndexOf('\n')) < 0)
			{
				while(i < 0)
				{
					FillBucket();
					i = bucket.IndexOf('\n');
				}
			}

			buf = bucket.Substring(0, i);
			bucket = bucket.Substring(i + 1);

			return buf;
		}


		// Any time a command is sent, use ReadResponse() to get the response
		// from the server. The variable responseStr holds the entire string and
		// the variable response holds the response number.
		private void ReadResponse()
		{
			string buf;
			messages = "";

			while(true)
			{
				//buf = GetLineFromBucket();
				buf = GetLineFromBucket();

#if (FTP_DEBUG)
				Console.WriteLine(buf);
#endif
				// the server will respond with "000-Foo bar" on multi line responses
				// "000 Foo bar" would be the last line it sent for that response.
				// Better example:
				// "000-This is a multiline response"
				// "000-Foo bar"
				// "000 This is the end of the response"
				if (Regex.Match(buf, "^[0-9]+ ").Success)
				{
					responseStr = buf;
					response = int.Parse(buf.Substring(0, 3));
					break;
				}
				else
					messages += Regex.Replace(buf, "^[0-9]+-", "") + "\n";
			}
		}


		// if you add code that needs a data socket, i.e. a PASV or PORT command required,
		// call this function to do the dirty work. It sends the PASV or PORT command,
		// parses out the port and ip info and opens the appropriate data socket
		// for you. The socket variable is private Socket data_socket. Once you
		// are done with it, be sure to call CloseDataSocket()
		private void OpenDataSocket()
		{
			if (passive_mode)		// #######################################
			{
				string[] pasv;
				string server;
				int port;

				Connect();
				SendCommand("PASV");
				ReadResponse();
				if (response != 227)
					Fail();

				try
				{
					int i1, i2;

					i1 = responseStr.IndexOf('(') + 1;
					i2 = responseStr.IndexOf(')') - i1;
					pasv = responseStr.Substring(i1, i2).Split(',');
				}
				catch(Exception)
				{
					Disconnect();
					throw new Exception("Malformed PASV response: " + responseStr);
				}

				if (pasv.Length < 6)
				{
					Disconnect();
					throw new Exception("Malformed PASV response: " + responseStr);
				}

				server = String.Format("{0}.{1}.{2}.{3}", pasv[0], pasv[1], pasv[2], pasv[3]);
				port = (int.Parse(pasv[4]) << 8) + int.Parse(pasv[5]);

				try
				{
#if (FTP_DEBUG)
					Console.WriteLine("Data socket: {0}:{1}", server, port);
#endif
					CloseDataSocket();
					
#if (FTP_DEBUG)
					Console.WriteLine("Creating socket...");
#endif
					data_sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
					
#if (FTP_DEBUG)
					Console.WriteLine("Resolving host");
#endif

					data_ipEndPoint = new IPEndPoint(Dns.GetHostEntry(server).AddressList[0], port);

					
#if (FTP_DEBUG)
					Console.WriteLine("Connecting..");
#endif
					data_sock.Connect(data_ipEndPoint);

#if (FTP_DEBUG)
					Console.WriteLine("Connected.");
#endif
				}
				catch(Exception ex)
				{
					throw new Exception("Failed to connect for data transfer: " + ex.Message);
				}
			}
			else		// #######################################
			{
				Connect();

				try
				{
#if (FTP_DEBUG)
					Console.WriteLine("Data socket (active mode)");
#endif
					CloseDataSocket();
					
#if (FTP_DEBUG)
					Console.WriteLine("Creating listening socket...");
#endif
					listening_sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

#if (FTP_DEBUG)
					Console.WriteLine("Binding it to local address/port");
#endif
					// for the PORT command we need to send our IP address; let's extract it
					// from the LocalEndPoint of the main socket, that's already connected
					string sLocAddr = main_sock.LocalEndPoint.ToString();
					int ix = sLocAddr.IndexOf(':');
					if (ix < 0)
					{
						throw new Exception("Failed to parse the local address: " + sLocAddr);
					}
					string sIPAddr = sLocAddr.Substring(0, ix);
					// let the system automatically assign a port number (setting port = 0)
					System.Net.IPEndPoint localEP = new IPEndPoint(IPAddress.Parse(sIPAddr), 0);

					listening_sock.Bind(localEP);
					sLocAddr = listening_sock.LocalEndPoint.ToString();
					ix = sLocAddr.IndexOf(':');
					if (ix < 0)
					{
						throw new Exception("Failed to parse the local address: " + sLocAddr);
					}
					int nPort = int.Parse(sLocAddr.Substring(ix + 1));
#if (FTP_DEBUG)
					Console.WriteLine("Listening on {0}:{1}", sIPAddr, nPort);
#endif
					// start to listen for a connection request from the host (note that
					// Listen is not blocking) and send the PORT command
					listening_sock.Listen(1);
					string sPortCmd = string.Format("PORT {0},{1},{2}", 
													sIPAddr.Replace('.', ','),
													nPort / 256, nPort % 256);
					SendCommand(sPortCmd);
					ReadResponse();
					if (response != 200)
						Fail();
				}
				catch(Exception ex)
				{
					throw new Exception("Failed to connect for data transfer: " + ex.Message);
				}
			}
		}


		private void ConnectDataSocket()		// #######################################
		{
			if (data_sock != null)		// already connected (always so if passive mode)
				return;

			try
			{
#if (FTP_DEBUG)
				Console.WriteLine("Accepting the data connection.");
#endif
				data_sock = listening_sock.Accept();	// Accept is blocking
				listening_sock.Close();
				listening_sock = null;

				if (data_sock == null)
				{
					throw new Exception("Winsock error: " + 
						Convert.ToString(System.Runtime.InteropServices.Marshal.GetLastWin32Error()) );
				}
#if (FTP_DEBUG)
				Console.WriteLine("Connected.");
#endif
			}
			catch(Exception ex)
			{
				throw new Exception("Failed to connect for data transfer: " + ex.Message);
			}
		}


		private void CloseDataSocket()
		{
#if (FTP_DEBUG)
			Console.WriteLine("Attempting to close data channel socket...");
#endif
			if (data_sock != null)
			{
				if (data_sock.Connected)
				{
#if (FTP_DEBUG)
						Console.WriteLine("Closing data channel socket!");
#endif	
						data_sock.Close();
#if (FTP_DEBUG)
						Console.WriteLine("Data channel socket closed!");
#endif
				}
				data_sock = null;
			}

			data_ipEndPoint = null;
		}
		/// <summary>
		/// Closes all connections to the ftp server
		/// </summary>
		public void Disconnect()
		{
			CloseDataSocket();

			if (main_sock != null)
			{
				if (main_sock.Connected)
				{
					SendCommand("QUIT");
					main_sock.Close();
				}
				main_sock = null;
			}

			if (file != null)
				file.Close();

			main_ipEndPoint = null;
			file = null;
		}
		/// <summary>
		/// Connect to a ftp server
		/// </summary>
		/// <param name="server">IP or hostname of the server to connect to</param>
		/// <param name="port">Port number the server is listening on</param>
		/// <param name="user">Account name to login as</param>
		/// <param name="pass">Password for the account specified</param>
		public void Connect(string server, int port, string user, string pass)
		{
			this.server = server;
			this.user = user;
			this.pass = pass;
			this.port = port;

			Connect();
		}
		/// <summary>
		/// Connect to a ftp server
		/// </summary>
		/// <param name="server">IP or hostname of the server to connect to</param>
		/// <param name="user">Account name to login as</param>
		/// <param name="pass">Password for the account specified</param>
		public void Connect(string server, string user, string pass)
		{
			this.server = server;
			this.user = user;
			this.pass = pass;

			Connect();
		}
		/// <summary>
		/// Connect to an ftp server
		/// </summary>
		public void Connect()
		{
			if (server == null)
				throw new Exception("No server has been set.");
			if (user == null)
				throw new Exception("No username has been set.");

			if (main_sock != null)
				if (main_sock.Connected)
					return;

			main_sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
			main_ipEndPoint = new IPEndPoint(Dns.GetHostEntry(server).AddressList[0], port);
			
			try
			{
				main_sock.Connect(main_ipEndPoint);	
			}
			catch(Exception ex)
			{
				throw new Exception(ex.Message);
			}

			ReadResponse();
			if (response != 220)
				Fail();

			SendCommand("USER " + user);
			ReadResponse();

			switch(response)
			{
				case 331:
					if (pass == null)
					{
						Disconnect();
						throw new Exception("No password has been set.");
					}
					SendCommand("PASS " + pass);
					ReadResponse();
					if (response != 230)
						Fail();
					break;
				case 230:
					break;
			}
			
			return;
		}
		/// <summary>
		/// Retrieves a list of files from the ftp server
		/// </summary>
		/// <returns>An ArrayList of files</returns>
		public ArrayList List()
		{
			Byte[] bytes = new Byte[512];
			string file_list = "";
			long bytesgot = 0;
			int msecs_passed = 0;
			ArrayList list = new ArrayList();
		
			Connect();
			OpenDataSocket();
			SendCommand("LIST");
			ReadResponse();

			//FILIPE MADUREIRA.
			//Added response 125
			switch(response)
			{
				case 125:
				case 150:
					break;
				default:
					CloseDataSocket();
					throw new Exception(responseStr);
			}
			ConnectDataSocket();		// #######################################

			while(data_sock.Available < 1)
			{
				System.Threading.Thread.Sleep(50);
				msecs_passed += 50;
				// this code is just a fail safe option 
				// so the code doesn't hang if there is 
				// no data comming.
				if (msecs_passed > (timeout / 10))
				{
					//CloseDataSocket();
					//throw new Exception("Timed out waiting on server to respond.");
					
					//FILIPE MADUREIRA.
					//If there are no files to list it gives timeout.
					//So I wait less time and if no data is received, means that there are no files
					break;//Maybe there are no files
				}
			}

			while(data_sock.Available > 0)
			{
				bytesgot = data_sock.Receive(bytes, bytes.Length, 0);
				file_list += Encoding.ASCII.GetString(bytes, 0, (int)bytesgot);
				System.Threading.Thread.Sleep(50); // *shrug*, sometimes there is data comming but it isn't there yet.
			}
			
			CloseDataSocket();

			ReadResponse();
			if (response != 226)
				throw new Exception(responseStr);

			foreach(string f in file_list.Split('\n'))
			{
				if (f.Length > 0 && !Regex.Match(f, "^total").Success)
					list.Add(f.Substring(0, f.Length - 1));
			}

			return list;
		}
		/// <summary>
		/// Gets a file list only
		/// </summary>
		/// <returns>ArrayList of files only</returns>
		public ArrayList ListFiles()
		{
			ArrayList list = new ArrayList();

			foreach(string f in List())
			{
				//FILIPE MADUREIRA
				//In Windows servers it is identified by <DIR>
				if ((f.Length > 0))
				{
					if ((f[0] != 'd') && (f.ToUpper().IndexOf("<DIR>") < 0))
						list.Add(f);
				}
			}

			return list;
		}
		/// <summary>
		/// Gets a directory list only
		/// </summary>
		/// <returns>ArrayList of directories only</returns>
		public ArrayList ListDirectories()
		{
			ArrayList list = new ArrayList();

			foreach(string f in List())
			{
				//FILIPE MADUREIRA
				//In Windows servers it is identified by <DIR>
				if (f.Length > 0)
				{
					if ((f[0] == 'd') || (f.ToUpper().IndexOf("<DIR>") >= 0))
						list.Add(f);
				}
			}

			return list;
		}
		/// <summary>
		/// Returns the 'Raw' DateInformation in ftp format. (YYYYMMDDhhmmss). Use GetFileDate to return a DateTime object as a better option.
		/// </summary>
		/// <param name="fileName">Remote FileName to Query</param>
		/// <returns>Returns the 'Raw' DateInformation in ftp format</returns>
		public string GetFileDateRaw(string fileName)
		{
			Connect();
			
			SendCommand("MDTM " + fileName);
			ReadResponse();
			if(response != 213)
			{
#if (FTP_DEBUG)
				Console.Write("\r" + responseStr);
#endif
				throw new Exception(responseStr);
			}
			
			return (this.responseStr.Substring(4));
		}
		/// <summary>
		/// GetFileDate will query the ftp server for the date of the remote file.
		/// </summary>
		/// <param name="fileName">Remote FileName to Query</param>
		/// <returns>DateTime of the Input FileName</returns>
		public DateTime GetFileDate(string fileName)
		{
			return ConvertFTPDateToDateTime(GetFileDateRaw(fileName));
		}

		private DateTime ConvertFTPDateToDateTime(string input)
		{
			if(input.Length < 14)
				throw new ArgumentException("Input Value for ConvertFTPDateToDateTime method was too short.");
			
			//YYYYMMDDhhmmss": 
			int year = Convert.ToInt16(input.Substring(0,4));
			int month = Convert.ToInt16(input.Substring(4,2));
			int day = Convert.ToInt16(input.Substring(6,2));
			int hour = Convert.ToInt16(input.Substring(8,2));
			int min = Convert.ToInt16(input.Substring(10,2));
			int sec = Convert.ToInt16(input.Substring(12,2));

			return new DateTime(year, month, day, hour, min, sec);
		}
		/// <summary>
		/// Get the working directory on the ftp server
		/// </summary>
		/// <returns>The working directory</returns>
		public string GetWorkingDirectory()
		{
			//PWD - print working directory
			Connect();
			SendCommand("PWD");
			ReadResponse();

			if(response != 257)
				throw new Exception(responseStr);
			
			string pwd;
			try
			{
				pwd = responseStr.Substring(responseStr.IndexOf("\"", 0) + 1);//5);
				pwd = pwd.Substring(0, pwd.LastIndexOf("\""));
				pwd = pwd.Replace("\"\"", "\""); // directories with quotes in the name come out as "" from the server
			}
			catch(Exception ex)
			{
				throw new Exception("Uhandled PWD response: " + ex.Message);
			}

			return pwd;
		}
		/// <summary>
		/// Change to another directory on the ftp server
		/// </summary>
		/// <param name="path">Directory to change to</param>
		public void ChangeDir(string path)
		{
			Connect();
			SendCommand("CWD " + path);
			ReadResponse();
			if (response != 250)
			{
#if (FTP_DEBUG)
				Console.Write("\r" + responseStr);
#endif
				throw new Exception(responseStr);
			}
		}
		/// <summary>
		/// Create a directory on the ftp server
		/// </summary>
		/// <param name="dir">Directory to create</param>
		public void MakeDir(string dir)
		{
			Connect();
			SendCommand("MKD " + dir);
			ReadResponse();
			
			switch(response)
			{
				case 257:
				case 250:
					break;
				default:
#if (FTP_DEBUG)
                    Console.Write("\r" + responseStr);
#endif
					throw new Exception(responseStr);
			}
		}
		/// <summary>
		/// Remove a directory from the ftp server
		/// </summary>
		/// <param name="dir">Name of directory to remove</param>
		public void RemoveDir(string dir)
		{
			Connect();
			SendCommand("RMD " + dir);
			ReadResponse();
			if (response != 250)
			{
#if (FTP_DEBUG)
				Console.Write("\r" + responseStr);
#endif
				throw new Exception(responseStr);
			}
		}
		/// <summary>
		/// Remove a file from the ftp server
		/// </summary>
		/// <param name="filename">Name of the file to delete</param>
		public void RemoveFile(string filename)
		{
			Connect();
			SendCommand("DELE " + filename);
			ReadResponse();
			if (response != 250)
			{
#if (FTP_DEBUG)
				Console.Write("\r" + responseStr);
#endif
				throw new Exception(responseStr);
			}
		}
		/// <summary>
		/// Rename a file on the ftp server
		/// </summary>
		/// <param name="oldfilename">Old file name</param>
		/// <param name="newfilename">New file name</param>
		public void RenameFile(string oldfilename, string newfilename)		// #######################################
		{
			Connect();
			SendCommand("RNFR " + oldfilename);
			ReadResponse();
			if (response != 350)
			{
#if (FTP_DEBUG)
				Console.Write("\r" + responseStr);
#endif
				throw new Exception(responseStr);
			}
			else
			{
				SendCommand("RNTO " + newfilename);
				ReadResponse();
				if (response != 250)
				{
#if (FTP_DEBUG)
					Console.Write("\r" + responseStr);
#endif
					throw new Exception(responseStr);
				}
			}
		}
		/// <summary>
		/// Get the size of a file (Provided the ftp server supports it)
		/// </summary>
		/// <param name="filename">Name of file</param>
		/// <returns>The size of the file specified by filename</returns>
		public long GetFileSize(string filename)
		{
			Connect();
            SendCommand("TYPE I");
            ReadResponse();
			SendCommand("SIZE " + filename);
			ReadResponse();
			if (response != 213)
			{
#if (FTP_DEBUG)
				Console.Write("\r" + responseStr);
#endif
				throw new Exception(responseStr);
			}
            
			return Int64.Parse(responseStr.Substring(4));
		}
		/// <summary>
		/// Open an upload with no resume if it already exists
		/// </summary>
		/// <param name="filename">File to upload</param>
		public void OpenUpload(string filename)
		{
			OpenUpload(filename, filename, false);
		}
		/// <summary>
		/// Open an upload with no resume if it already exists
		/// </summary>
		/// <param name="filename">Local file to upload (Can include path to file)</param>
		/// <param name="remotefilename">Filename to store file as on ftp server</param>
		public void OpenUpload(string filename, string remotefilename)
		{
			OpenUpload(filename, remotefilename, false);
		}
		/// <summary>
		/// Open an upload with resume support
		/// </summary>
		/// <param name="filename">Local file to upload (Can include path to file)</param>
		/// <param name="resume">Attempt resume if exists</param>
		public void OpenUpload(string filename, bool resume)
		{
			OpenUpload(filename, filename, resume);
		}
		/// <summary>
		/// Open an upload with resume support
		/// </summary>
		/// <param name="filename">Local file to upload (Can include path to file)</param>
		/// <param name="remote_filename">Filename to store file as on ftp server</param>
		/// <param name="resume">Attempt resume if exists</param>
		public void OpenUpload(string filename, string remote_filename, bool resume)
		{
			Connect();
			SetBinaryMode(true);
			OpenDataSocket();

			bytes_total = 0;

			try
			{
				file = new FileStream(filename, FileMode.Open);
			}
			catch(Exception ex)
			{
				file = null;
				throw new Exception(ex.Message);
			}

			file_size = file.Length;

			if (resume)
			{
				long size = GetFileSize(remote_filename);
				SendCommand("REST " + size);
				ReadResponse();
				if (response == 350)
					file.Seek(size, SeekOrigin.Begin);
			}
			
			SendCommand("STOR " + remote_filename);
			ReadResponse();

			switch(response)
			{
				case 125:
				case 150:
					break;
				default:
					file.Close();
					file = null;
					throw new Exception(responseStr);
			}
			ConnectDataSocket();		// #######################################	

			return;
		}
		/// <summary>
		/// Download a file with no resume
		/// </summary>
		/// <param name="filename">Remote file name</param>
		public void OpenDownload(string filename)
		{
			OpenDownload(filename, filename, false);
		}
		/// <summary>
		/// Download a file with optional resume
		/// </summary>
		/// <param name="filename">Remote file name</param>
		/// <param name="resume">Attempt resume if file exists</param>
		public void OpenDownload(string filename, bool resume)
		{
			OpenDownload(filename, filename, resume);
		}
		/// <summary>
		/// Download a file with no attempt to resume
		/// </summary>
		/// <param name="filename">Remote filename</param>
		/// <param name="localfilename">Local filename (Can include path to file)</param>
		public void OpenDownload(string filename, string localfilename)
		{
			OpenDownload(filename, localfilename, false);
		}
		/// <summary>
		/// Open a file for download
		/// </summary>
		/// <param name="remote_filename">The name of the file on the FTP server</param>
		/// <param name="local_filename">The name of the file to save as (Can include path to file)</param>
		/// <param name="resume">Attempt resume if file exists</param>
		public void OpenDownload(string remote_filename, string local_filename, bool resume)
		{
			Connect();
			SetBinaryMode(true);

			bytes_total = 0;
			
			try
			{
				file_size = GetFileSize(remote_filename);
			}
			catch
			{
				file_size = 0;
			}
			
			if (resume && File.Exists(local_filename))
			{
				try
				{
					file = new FileStream(local_filename, FileMode.Open);
				}
				catch(Exception ex)
				{
					file = null;
					throw new Exception(ex.Message);
				}

				SendCommand("REST " + file.Length);
				ReadResponse();
				if (response != 350)
					throw new Exception(responseStr);
				file.Seek(file.Length, SeekOrigin.Begin);
				bytes_total = file.Length;
			}
			else
			{
				try
				{
					file = new FileStream(local_filename, FileMode.Create);
				}
				catch(Exception ex)
				{
					file = null;
					throw new Exception(ex.Message);
				}
			}

			OpenDataSocket();
			SendCommand("RETR " + remote_filename);
			ReadResponse();
			
			switch(response)
			{
				case 125:
				case 150:
					break;
				default:
					file.Close();
					file = null;
					throw new Exception(responseStr);
			}
			ConnectDataSocket();		// #######################################	

			return;
		}
		/// <summary>
		/// Upload the file, to be used in a loop until file is completely uploaded
		/// </summary>
		/// <returns>Bytes sent</returns>
		public long DoUpload()
		{
			Byte[] bytes = new Byte[512];
			long bytes_got;

			try
			{
				bytes_got = file.Read(bytes, 0, bytes.Length);
				bytes_total += bytes_got;
				data_sock.Send(bytes, (int)bytes_got, 0);

				if(bytes_got <= 0)
				{
					// the upload is complete or an error occured
					file.Close();
					file = null;
				
					CloseDataSocket();
					ReadResponse();
					switch(response)
					{
						case 226:
						case 250:
							break;
						default:
							throw new Exception(responseStr);
					}
				
					SetBinaryMode(false);
				}
			}
			catch(Exception ex)
			{
				file.Close();
				file = null;
				CloseDataSocket();
				ReadResponse();
				SetBinaryMode(false);
				throw ex;
			}

			return bytes_got;
		}
		/// <summary>
		/// Download a file, to be used in a loop until the file is completely downloaded
		/// </summary>
		/// <returns>Number of bytes recieved</returns>
		public long DoDownload()
		{
			Byte[] bytes = new Byte[512];
			long bytes_got;
			
			try
			{
				bytes_got = data_sock.Receive(bytes, bytes.Length, 0);

				if(bytes_got <= 0)
				{
					// the download is done or an error occured
					CloseDataSocket();
					file.Close();
					file = null;
				
					ReadResponse();
					switch(response)
					{
						case 226:
						case 250:
							break;
						default:
							throw new Exception(responseStr);
					}
				
					SetBinaryMode(false);

					return bytes_got;
				}

				file.Write(bytes, 0, (int)bytes_got);
				bytes_total += bytes_got;
			}
			catch(Exception ex)
			{
				CloseDataSocket();
				file.Close();
				file = null;
				ReadResponse();
				SetBinaryMode(false);
				throw ex;
			}

			return bytes_got;
		}
	}
}