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FTP component written with fully managed code

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7 May 20021 min read 851.1K   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

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


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Comments and Discussions

 
GeneralRe: Simultaneous Downloads? Pin
Jason Gerard22-Aug-02 3:28
Jason Gerard22-Aug-02 3:28 
GeneralRe: Simultaneous Downloads? Pin
Jon Rista26-Nov-02 16:21
Jon Rista26-Nov-02 16:21 
GeneralRe: Simultaneous Downloads? Pin
Matt Philmon26-Nov-02 16:35
Matt Philmon26-Nov-02 16:35 
GeneralRe: Simultaneous Downloads? Pin
Alex Kwok13-Aug-02 18:33
Alex Kwok13-Aug-02 18:33 
GeneralGeneral Help Pin
OnuSigep19-Jul-02 10:05
OnuSigep19-Jul-02 10:05 
GeneralRe: General Help Pin
Anonymous9-Aug-02 6:24
Anonymous9-Aug-02 6:24 
GeneralRe: General Help Pin
Matt Philmon13-Aug-02 18:28
Matt Philmon13-Aug-02 18:28 
GeneralRe: General Help Pin
Anonymous13-Nov-02 23:41
Anonymous13-Nov-02 23:41 
GeneralLicensing Pin
Scott Hernandez18-Jul-02 7:49
Scott Hernandez18-Jul-02 7:49 
GeneralRe: Licensing Pin
Alex Kwok18-Jul-02 21:23
Alex Kwok18-Jul-02 21:23 
GeneralTimestamp Pin
8-Jul-02 0:42
suss8-Jul-02 0:42 
Generalcreate directory Pin
4-Jul-02 3:25
suss4-Jul-02 3:25 
GeneralRe: create directory Pin
Alex Kwok4-Jul-02 4:36
Alex Kwok4-Jul-02 4:36 
GeneralRe: create directory Pin
romain9-Jul-02 4:16
romain9-Jul-02 4:16 
GeneralRe: create directory Pin
Alex Kwok9-Jul-02 15:57
Alex Kwok9-Jul-02 15:57 
GeneralRe: create directory Pin
romain9-Jul-02 22:13
romain9-Jul-02 22:13 
GeneralRe: create directory Pin
romain9-Jul-02 22:09
romain9-Jul-02 22:09 
GeneralRe: create directory Pin
Uwe Keim13-Sep-02 0:13
sitebuilderUwe Keim13-Sep-02 0:13 
GeneralRe: create directory Pin
Greg Arzoomanian9-Apr-03 16:55
sussGreg Arzoomanian9-Apr-03 16:55 
GeneralHelp On . Pin
linkesh3-Jul-02 23:43
linkesh3-Jul-02 23:43 
QuestionActive Mode? Pin
Rogerw18-Jun-02 0:48
Rogerw18-Jun-02 0:48 
AnswerRe: Active Mode? Pin
Alex Kwok18-Jun-02 4:15
Alex Kwok18-Jun-02 4:15 
GeneralRe: Active Mode? Pin
Matt Philmon13-Aug-02 18:22
Matt Philmon13-Aug-02 18:22 
GeneralRe: Active Mode? Pin
Alex Kwok13-Aug-02 18:28
Alex Kwok13-Aug-02 18:28 
GeneralParseLineList Problem Pin
6-Jun-02 6:40
suss6-Jun-02 6:40 

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