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FTP component written with fully managed code

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7 May 20021 min read 851.2K   14.7K   178   251
A .NET FTP component

Recently, I needed to write a program which could automatically download files from an FTP server. Unfortunately the .NET Framework lacks good support for FTP services. Although a few companies have already written libraries which can be used directly, the price is really too high for poor men like me. As a result, I decided to write my own FTP library and here it is.

Disclaimer

This FTP component is an incomplete implementation of my design nor has it been fully tested. Please keep in mind it may contain bugs or even design flaws.

Connect to FTP server

C#
FtpSession session = new FtpSession();
session.Server = "localhost";
session.Port   = 21; //not required if using the default ftp port 21
session.Connect("anonymous", "someone@somewhere.com");

Enum subdirectories and files

C#
/*
* It is possible an incorrect list will be returned.
* In this case, you need to add your own regular expression to 
* interpret the list result (try to find it within ftpdirectory.cs)
*/
FtpDirectory root = session.RootDirectory;
foreach(FtpDirectory d in root.SubDirectories)
    //do something

    foreach(FtpFile f in root.Files)
        //do something

        /*
         * Only CurrentDirectory's item can be legally used.
         * Do not save down FtpDirectory and FtpFile for later use
         * unless you are sure they belongs to CurrentDirectory.
         * Here is some sample may cause problems
         */
        FtpDirectory d1 = session.CurrentDirectory.FindSubdirectory("somesubdir");
        FtpDirectory d2 = session.CurrentDirectory.FindSubdirectory("othersubdir");
        session.CurrentDirectory = d2;
        
        /*
         * Following 2 line will cause problem since CurrentDirectory 
         * is not d1's parent anymore
         */
        foreach(FtpDirectory d in d1) 
            //dosomthing

Change current directory

C#
session.CurrentDirectory = somesubdirectory

Upload file

C#
//Blocking call
session.CurrentDirectory.PutFile("somelocalfile");
    
//Async call using callback
session.CurrentDirectory.BeginPutFile("somelocalfile", +
    new FtpAsyncDelegate(yourcallback);
    
//Async call using event
session.EndPutFile += new FtpFileEventHandler(yourhandler);
session.CurrectDirectory.BeginPutFile("somelocalfile");
        
    //Manually upload the file
    FileInfo fi = new FileInfo(localfilefullpath);
    Stream r = File.OpenRead(fi.FullName);

    // actually will return a FtpOutputDataStream object
    Stream w = session.CurrentDirectory.CreateDataStream(fi.Name); 
    int readed;
    byte[] buff = new byte[4096];
    while((readed=r.Read(buff, 0, 4096) != 0)
	    w.Write(buff, 0, readed);
    /*
    * Must call FtpDataStream.Close().
    * This is because it will try to read the file transfer 
    * result from FTP server.
    */
    w.Close();
    s.Close();

Download file

C#
//Blocking call
session.CurrentDirectory.GetFile("someremotefile");
    
//Async call using callback
session.CurrentDirectory.BeginGetFile("someremotefile", + 
    new FtpAsyncDelegate(yourcallback);
    
//Async call using event
session.EngGetFile += new FtpFileEventHandler(yourhandler);
session.CurrectDirectory.BeginGetFile("someremotefile");

//Manually download a file
Stream r = File.OpenWrite(localfilepath);

    FtpFile remoteFile = session.CurrentDirectory.FindFile(remotefilename);
    Stream w = remoteFile.GetOutputDataStream();
    int readed;
    byte[] buff = new byte[4096];
    while((readed=r.Read(buff, 0, 4096) != 0)
        w.Write(buff, 0, readed);
    /*
    * Must call FtpDataStream.Close().
    * This is because it will try to read the file transfer 
    * result from FTP server.
    */
    w.Close();
    s.Close();

Create a new file in ftp server

C#
//method 1
session.CurrentDirectory.CreateFile(newfilename);
        
//method 2
Stream s = session.CurrentDirectory.CreateFileStream(newfilename);
// do something with s
s.Close();

Delete a file from ftp server

C#
//method 1
session.CurrentDirectory.RemoveFile(remotefilename);
        
//method 2
IFtpItem item = session.CurrentDirectory.FindItem(remotefilename)
if(item != null)
    session.CurrentDirectory.RemoveItem(item);

Delete a subdirectory

C#
//method 1
session.CurrentDirectory.RemoveSubdir(subdirectoryname);

//method 2
IFtpItem item = session.CurrentDirectory.FindItem(sub directoryname)
if(item != null)
    session.CurrentDirectory.RemoveItem(item);

Refresh the content of ftp directory

C#
/*
* If you have saved down some some directory item(subdir or ftpfile).
* They will become invalid after you refresh the directory
*/
FtpFile f = session.CurrentDirectory.FindFile(somefile);
         
// you can not leagally use f anymore after the following line
session.CurrentDirectory.Refresh();

Rename a file or directory

C#
IFtpItem item = session.FindItem(directoryorfile);
if(item != null)
    session.RenameSubitem(item, newname);

Known Limitations

  • No support for active mode
  • No support for proxy server

Updates

  • Removed FileCollection and DirectoryCollection
  • Added support for VB's for each statement
  • VB client can directly access FtpDirectory.Files and FtpDirectory.SubDirectories with for each statement now.

Please send me a email if you find any bugs. Please include at least a description of the bug you have found. It will be nice if a testing program or even a solution is included.

Have fun.

License

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Comments and Discussions

 
GeneralRe: ftp.subdirectories and .files collections question Pin
Alex Kwok15-Jan-03 17:34
Alex Kwok15-Jan-03 17:34 
GeneralRe: ftp.subdirectories and .files collections question Pin
hilson6-Feb-03 5:10
hilson6-Feb-03 5:10 
GeneralRe: ftp.subdirectories and .files collections question Pin
Troy Taft5-Mar-03 4:50
Troy Taft5-Mar-03 4:50 
GeneralRe: ftp.subdirectories and .files collections question Pin
Radu Grama27-Mar-03 11:23
Radu Grama27-Mar-03 11:23 
GeneralCannot Find File Pin
Member 16681910-Jan-03 6:50
Member 16681910-Jan-03 6:50 
GeneralRe: Cannot Find File Pin
Alex Kwok10-Jan-03 17:59
Alex Kwok10-Jan-03 17:59 
GeneralRe: Cannot Find File Pin
13-Jan-03 3:58
suss13-Jan-03 3:58 
Generalvb.net User Totaly Lost Pin
theahmed5-Jan-03 13:29
theahmed5-Jan-03 13:29 
GeneralRe: vb.net User Totaly Lost Pin
theahmed5-Jan-03 19:11
theahmed5-Jan-03 19:11 
GeneralRe: vb.net User Totaly Lost Pin
theahmed5-Jan-03 19:12
theahmed5-Jan-03 19:12 
GeneralHow to use in VB.net Pin
anonymous200127-Jan-03 1:13
anonymous200127-Jan-03 1:13 
GeneralDirectory Pin
lunchan1-Jan-03 6:11
lunchan1-Jan-03 6:11 
GeneralDoes Not Work Pin
12nevr24-Dec-02 2:25
12nevr24-Dec-02 2:25 
GeneralRe: Does Not Work Pin
Troy Taft4-Mar-03 9:03
Troy Taft4-Mar-03 9:03 
GeneralActive FTP Mode Pin
CoolArsh118-Dec-02 9:52
CoolArsh118-Dec-02 9:52 
GeneralRe: Active FTP Mode Pin
Alex Kwok18-Dec-02 16:02
Alex Kwok18-Dec-02 16:02 
GeneralRe: Active FTP Mode Pin
Matt Philmon30-Jan-03 9:57
Matt Philmon30-Jan-03 9:57 
GeneralUpdating Oracle database Pin
Anonymous17-Dec-02 1:11
Anonymous17-Dec-02 1:11 
GeneralShowing and saving files Pin
Andrew Saxe10-Dec-02 4:22
sussAndrew Saxe10-Dec-02 4:22 
GeneralDual 220 lines on login makes it choke Pin
btimberl9-Dec-02 10:11
btimberl9-Dec-02 10:11 
GeneralRe: Dual 220 lines on login makes it choke Pin
5-Feb-03 21:54
suss5-Feb-03 21:54 
GeneralASP.NET and FTP component Pin
Gavi Narra9-Dec-02 9:04
Gavi Narra9-Dec-02 9:04 
GeneralRe: ASP.NET and FTP component Pin
Alex Kwok12-Dec-02 14:49
Alex Kwok12-Dec-02 14:49 
Generalcode Pin
cyrusv6-Dec-02 10:08
cyrusv6-Dec-02 10:08 
GeneralRe: code Pin
Alex Kwok6-Dec-02 14:40
Alex Kwok6-Dec-02 14:40 

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