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Change from C# FtpWebRequest FTP code to SFTP

I would really need some help to change from FTP transfer to SFTP. I added some lines in the comment but I'm new to programming and I don't know for sure what I also need to add to fix this problem. The programme works fine but at the moment you transfer your data via FTP. I read some questions here but for now, I couldn't find the right tipp rewrite the program to SFTP.
public class FTP
{
private System.ComponentModel.BackgroundWorker bw = null;
private long filesSize = 0;
private long uploadSize = 0;
private const int bufferLength = 2048;
public FTP()
{
}
public FTP(System.ComponentModel.BackgroundWorker thread, long allFilesSize)
{
bw = thread;
filesSize = allFilesSize;
}
public string ReadUserFile()
{
WebClient req = new WebClient();
req.Credentials = new NetworkCredential("", "");
try
{
byte[] newFileData = req.DownloadData();
return System.Text.Encoding.Default.GetString(newFileData);
}
catch
{
return null;
}
}
public void UploadFile(
string ftpServer, string filePath, string username, string password)
{
//Create SFTP request
//Sftp client = new Sftp();
//client.Connect(hostname);
//client.Login(username, password);
//Create FTP request
FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create();
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;
//Load the file
//
//Load the file
FileStream stream = File.OpenRead(filePath);
//Upload to Sftp Server
//client.PutFile();
//Upload file
Stream reqStream = request.GetRequestStream();
byte[] buffer = new byte[bufferLength];
int count = 0;
int readBytes = 0;
do
{
readBytes = stream.Read(buffer, 0, bufferLength);
reqStream.Write(buffer, 0, readBytes);
count += readBytes;
if (bw != null)
bw.ReportProgress(CalculateProgress());
}
while (readBytes != 0);
//Disconnect
//client.Disconnect();
stream.Close();
reqStream.Close();
}
private int CalculateProgress()
{
uploadSize += bufferLength;
return (Int32)(uploadSize/(filesSize / 100));
}
public void DeleteFile(
string ftpServer, string filePath, string username, string password)
{
//Create SFTP request
//Sftp client = new Sftp();
//client.Connect(hostname);
//client.Login(username, password);
//Create FTP request
FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create();
request.Method = WebRequestMethods.Ftp.DeleteFile;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
response.Close();
}
public string[] GetFileList(
string ftpServer, string username, string password)
{
string[] fileList;
StringBuilder result = new StringBuilder();
FtpWebRequest request;
try
{
request = (FtpWebRequest)FtpWebRequest.Create(new Uri());
request.UseBinary = true;
request.Credentials = new NetworkCredential(username, password);
request.Method = WebRequestMethods.Ftp.ListDirectory;
WebResponse response = request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string line = reader.ReadLine();
while (line != null)
{
if (line.StartsWith("./"))
line = line.Substring(2, line.Length - 2);
result.Append(line);
result.Append("\n");
line = reader.ReadLine();
}
result.Remove(result.ToString().LastIndexOf('\n'), 1);
reader.Close();
response.Close();
return result.ToString().Split('\n');
}
catch
{
//Error
fileList = null;
return fileList;
}
}

There's no simple way to switch from FTP to SFTP in C#/.NET, if you are currently using .NET FtpWebRequest API.
There's no support for SFTP in .NET framework.
You need 3rd party library: SFTP Libraries for .NET.
That also means that you basically need to scratch your current code and start from the very beginning. Not a single line in your current code would be useful for SFTP with any 3rd party library, as they have very different API to unusual FtpWebRequest.
There are libraries that offer an uniform interface to both FTP and SFTP protocols.
For example WinSCP .NET assembly supports FTP, FTPS, FTPES, SFTP and others (SCP, S3,
WebDAV and WebDAVS) over the same interface.
Though it is not a native .NET assembly. It's rather a thin wrapper over
a console application.
(I'm the author of WinSCP).

How to do multiple methods in one FTP connection

I have code set up to do an FTP PUT with a file to an FTP server. First I have a method that checks if the file exists at the target location. Then if it does I have another method that deletes the file. Then I perform the FTP PUT to the target location.
Currently, I'm performing these 3 methods by setting up 3 separate FTP connections to the same server. However, I want to perform all 3 methods with one connection to the server. The reason is because I'm getting the following error after opening multiple connections to same FTP server: "An existing connection was forcibly closed by the remote host."
Here are the 3 functions below. The first method, GetFileFromRemoteServer, is used to see if a file exists on the FTP server at target path. I use regex in some cases to get partial name match, or in other cases just do full name match.
I researched online that someone said it's possible to use the same ftp request object and just perform all methods you want and then close the connection. I tried to see if it works performing multiple methods on same request object and I got this error: This operation cannot be performed after the request has been submitted.
Is there a way to perform all of them using one connection to the server?
Thank you, I really appreciate your help!
public static List<FTPLineResult> GetFileFromRemoteServer(bool isSsl, string username, string password, string fileName, string dir, Regex regexPattern,
bool getSingleFile = false)
{
var output = new List<FTPLineResult>();
var parser = new FTPLineParser();
var isDone = false;
var request = (FtpWebRequest)WebRequest.Create(dir);
request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
request.ConnectionGroupName = ConfigurationManager.AppSettings["ftpConnectionGroup"];
request.KeepAlive = true;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
if (isSsl)
{
request.EnableSsl = true;
}
else
{
request.EnableSsl = false;
}
using (var response = (FtpWebResponse)request.GetResponse())
{
using (var responseStream = response.GetResponseStream())
{
using (var reader = new StreamReader(responseStream, Encoding.ASCII))
{
while (!isDone && !reader.EndOfStream)
{
var result = parser.Parse(reader.ReadLine());
//if "*" is in file name, which means get partial match, replacing * with real file name content
if (regexPattern != null)
{
if (regexPattern.IsMatch(result.Name.ToLower().Trim()))
{
output.Add(result);
}
}
else if (result.Name.ToLower().Trim() == fileName.ToLower().Trim())
{
output.Add(result);
isDone = true;
}
}
return output;
}
}
}
}
private void DeleteExistingTargetFile()
{
// Get the object used to communicate with the server.
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(_params.FinalFolderTarget);
request.Method = WebRequestMethods.Ftp.DeleteFile;
request.Credentials = new NetworkCredential(_params.Username, _params.Password);
request.UsePassive = true;
request.ConnectionGroupName = ConfigurationManager.AppSettings["ftpConnectionGroup"];
request.KeepAlive = true;
if (_params.IsSsl)
{
request.EnableSsl = true;
}
else
{
request.EnableSsl = false;
}
using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
{
var status = response.StatusDescription;
}
}
private void DoFtpPut(Dictionary<StatusEnum, string> statusDict)
{
int buffLength = 2048;
byte[] buff = new byte[buffLength];
System.IO.FileInfo _FileInfo = new System.IO.FileInfo(_params.SourceFilename);
var request = (FtpWebRequest)WebRequest.Create(new Uri(_params.TargetFilename));
request.Method = WebRequestMethods.Ftp.UploadFile;
request.ConnectionGroupName = ConfigurationManager.AppSettings["ftpConnectionGroup"];
request.KeepAlive = true;
request.Credentials = new NetworkCredential(_params.Username, _params.Password);
request.UsePassive = true;
if (_params.IsSsl)
{
request.EnableSsl = true;
}
else
{
request.EnableSsl = false;
}
using (var _Stream = request.GetRequestStream())
{
//read file one chunk at a time in order to avoid out of memory exception
using (var fileStream = _FileInfo.OpenRead())
{
var contentLen = fileStream.Read(buff, 0, buffLength);
while (contentLen != 0)
{
_Stream.Write(buff, 0, contentLen);
contentLen = fileStream.Read(buff, 0, buffLength);
}
}
}
statusDict[StatusEnum.ftpStatus] = Constants.SUCCESS_STATUS;
}

I couldn't figure out a way to do FTPPUT with only one connection using FtpWebRequest class. However, using FtpLib library allowed me to do exactly what I wanted, which was to check if file exists on ftp server target location, if it does then delete it, and then do ftp put, and finally move file to final location using a rename.
Here's where I downloaded ftplib library: ftplib.codeplex.com
Here's the code below:
using (FtpConnection ftp = new FtpConnection(host, _params.Username, _params.Password))
{
try
{
ftp.Open(); /* Open the FTP connection */
ftp.Login(); /* Login using previously provided credentials */
ftp.PutFile(_params.SourceFilename, _params.TargetFilename); /* upload /incoming/file.txt as file.txt to current executing directory, overwrite if it exists */
if (!ftp.DirectoryExists(_params.FinalDir)) /* check that a directory exists */
{
ftp.CreateDirectory(_params.FinalDir);
}
if (ftp.FileExists(_params.FinalLocation))
{
ftp.RemoveFile(_params.FinalLocation);
}
ftp.RenameFile(target, _params.FinalLocation);
statusDict[StatusEnum.ftpStatus] = Constants.SUCCESS_STATUS;
}
catch (Exception ex)
{
statusDict[StatusEnum.ftpStatus] = Constants.ERROR_STATUS;
}
}

How to recursively delete a folder with the files within using FtpWebRequest?

I want to delete a folder in FTP and it's files recursively.
Any example code do I can implement?

First you have to list all your files in your directory :
public static List<string> DirectoryListing(string Path, string ServerAdress, string Login, string Password)
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://" + ServerAdress + Path);
request.Credentials = new NetworkCredential(Login, Password);
request.Method = WebRequestMethods.Ftp.ListDirectory;
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream);
List<string> result = new List<string>();
while (!reader.EndOfStream)
{
result.Add(reader.ReadLine());
}
reader.Close();
response.Close();
return result;
}
Then you need a method to delete a single file (because you can delete a folder only if it's empty) :
public static void DeleteFTPFile(string Path, string ServerAdress, string Login, string Password)
{
FtpWebRequest clsRequest = (System.Net.FtpWebRequest)WebRequest.Create("ftp://" + ServerAdress + Path);
clsRequest.Credentials = new System.Net.NetworkCredential(Login, Password);
clsRequest.Method = WebRequestMethods.Ftp.DeleteFile;
string result = string.Empty;
FtpWebResponse response = (FtpWebResponse)clsRequest.GetResponse();
long size = response.ContentLength;
Stream datastream = response.GetResponseStream();
StreamReader sr = new StreamReader(datastream);
result = sr.ReadToEnd();
sr.Close();
datastream.Close();
response.Close();
}
And finally :
public static void DeleteFTPDirectory(string Path, string ServerAdress, string Login, string Password)
{
FtpWebRequest clsRequest = (System.Net.FtpWebRequest)WebRequest.Create("ftp://" + ServerAdress + Path);
clsRequest.Credentials = new System.Net.NetworkCredential(Login, Password);
List<string> filesList = DirectoryListing(Path, ServerAdress, Login, Password);
foreach (string file in filesList)
{
DeleteFTPFile(Path + file, ServerAdress, Login, Password);
}
clsRequest.Method = WebRequestMethods.Ftp.RemoveDirectory;
string result = string.Empty;
FtpWebResponse response = (FtpWebResponse)clsRequest.GetResponse();
long size = response.ContentLength;
Stream datastream = response.GetResponseStream();
StreamReader sr = new StreamReader(datastream);
result = sr.ReadToEnd();
sr.Close();
datastream.Close();
response.Close();
}
You can easily call this like that (for me those methods are in a class called "Ftp") :
Ftp.DeleteFTPDirectory(the_path_of_your_folder_in_ftp,your_server_address,your_ftp_login,your_ftp_password);
Of course, you'll need to customize those lines, but it worked perfectly for me :)

There's no support for recursive operations in the FtpWebRequest class (or any other FTP implementation in the .NET framework). You have to implement the recursion yourself:
List the remote directory
Iterate the entries, deleting files and recursing into subdirectories (listing them again, etc.)
Tricky part is to identify files from subdirectories. There's no way to do that in a portable way with the FtpWebRequest. The FtpWebRequest unfortunately does not support the MLSD command, which is the only portable way to retrieve directory listing with file attributes in FTP protocol. See also Checking if object on FTP server is file or directory.
Your options are:
Do an operation on a file name that is certain to fail for a file and to succeed for directory (or vice versa). I.e. you can try to download the "name". If that succeeds, it's a file, if that fails, it's a directory. But that can become a performance problem, when you have a large number of entries.
You may be lucky and in your specific case, you can tell a file from a directory by a file name (i.e. all your files have an extension, while subdirectories do not)
You use a long directory listing (LIST command = ListDirectoryDetails method) and try to parse a server-specific listing. Many FTP servers use *nix-style listing, where you identify a directory by the d at the very beginning of the entry. But many servers use a different format. The following example uses this approach (assuming the *nix format).
In this specific case, you can just try to delete the entry as a file. If deleting fails, try to list the entry as a directory. If the listing succeeds, you assume it's a folder and proceed accordingly. Unfortunately some servers do not error, when you try to list a file. They will just return a listing with a single entry for the file.
static void DeleteFtpDirectory(string url, NetworkCredential credentials)
{
FtpWebRequest listRequest = (FtpWebRequest)WebRequest.Create(url);
listRequest.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
listRequest.Credentials = credentials;
List<string> lines = new List<string>();
using (FtpWebResponse listResponse = (FtpWebResponse)listRequest.GetResponse())
using (Stream listStream = listResponse.GetResponseStream())
using (StreamReader listReader = new StreamReader(listStream))
{
while (!listReader.EndOfStream)
{
lines.Add(listReader.ReadLine());
}
}
foreach (string line in lines)
{
string[] tokens =
line.Split(new[] { ' ' }, 9, StringSplitOptions.RemoveEmptyEntries);
string name = tokens[8];
string permissions = tokens[0];
string fileUrl = url + name;
if (permissions[0] == 'd')
{
DeleteFtpDirectory(fileUrl + "/", credentials);
}
else
{
FtpWebRequest deleteRequest = (FtpWebRequest)WebRequest.Create(fileUrl);
deleteRequest.Method = WebRequestMethods.Ftp.DeleteFile;
deleteRequest.Credentials = credentials;
deleteRequest.GetResponse();
}
}
FtpWebRequest removeRequest = (FtpWebRequest)WebRequest.Create(url);
removeRequest.Method = WebRequestMethods.Ftp.RemoveDirectory;
removeRequest.Credentials = credentials;
removeRequest.GetResponse();
}
The url should be like ftp://example.com/directory/to/delete/
Or use a 3rd party library that supports recursive operations.
For example with WinSCP .NET assembly you can delete whole directory with a single call to Session.RemoveFiles:
// Setup session options
SessionOptions sessionOptions = new SessionOptions
{
Protocol = Protocol.Ftp,
HostName = "example.com",
UserName = "user",
Password = "mypassword",
};
using (Session session = new Session())
{
// Connect
session.Open(sessionOptions);
// Delete folder
session.RemoveFiles("/home/user/foldertoremove").Check();
}
Internally, WinSCP uses the MLSD command, if supported by the server. If not, it uses the LIST command and supports dozens of different listing formats.
(I'm the author of WinSCP)

Nice Little example you can find here:
http://msdn.microsoft.com/en-us/library/system.net.ftpwebrequest.aspx
In the example they used WebRequestMethods.Ftp.UploadFile class to direct what kind of operation they want to do.
Use the WebRequestMethods.Ftp.RemoveDirectory method once you have a handle on the parent directory you want to delete:
http://msdn.microsoft.com/en-us/library/system.net.webrequestmethods.ftp.aspx

None of the solutions really worked on different types of servers except using
System.Net.FtpClient
using System.Net.FtpClient;
static void DeleteFtpDirectoryAndContent(string host, string path, NetworkCredential credentials, string dontDeleteFileUrl)
{
using (FtpClient conn = new FtpClient())
{
conn.Host = host;
conn.Credentials = credentials;
foreach (FtpListItem item in conn.GetListing(path, FtpListOption.AllFiles | FtpListOption.ForceList))
{
switch (item.Type)
{
case FtpFileSystemObjectType.Directory:
conn.DeleteDirectory(item.FullName, true, FtpListOption.AllFiles | FtpListOption.ForceList);
break;
case FtpFileSystemObjectType.File:
if (!dontDeleteFileUrl.EndsWith(item.FullName, StringComparison.InvariantCultureIgnoreCase))
conn.DeleteFile(item.FullName);
break;
}
}
}
}

Unable to rename file with ftp methods when current user directory is different from root

Remark: due to spam prevention mechanizm I was forced to replace the beginning of the Uris from ftp:// to ftp.
I've got following problem. I have to upload file with C# ftp method and afterwards rename it. Easy, right? :)
Ok, let's say my ftp host is like this:
ftp.contoso.com
and after logging in, current directory is set to:
users/name
So, what I'm trying to achieve is to log in, upload file to current directory as file.ext.tmp and after upload is successful, rename the file to file.ext
The whole difficulty is, as I guess, to properly set the request Uri for FtpWebRequest.
MSDN states:
The URI may be relative or absolute. If the URI is of the form "ftp://contoso.com/%2fpath" (%2f is an escaped '/'), then the URI is absolute, and the current directory is /path. If, however, the URI is of the form "ftp://contoso.com/path", first the .NET Framework logs into the FTP server (using the user name and password set by the Credentials property), then the current directory is set to UserLoginDirectory/path.
Ok, so I upload file with the following URI:
ftp.contoso.com/file.ext.tmp
Great, the file lands where I wanted it to be: in directory "users/name"
Now, I want to rename the file, so I create web request with following Uri:
ftp.contoso.com/file.ext.tmp
and specify rename to parameter as:
file.ext
and this gives me 550 error: file not found, no permissions, etc.
I traced this in Microsoft Network Monitor and it gave me:
Command: RNFR, Rename from
CommandParameter: /file.ext.tmp
Ftp: Response to Port 53724, '550 File /file.ext.tmp not found'
as if it was looking for the file in the root directory - not in the current directory.
I renamed the file manually using Total Commander and the only difference was that CommandParameter was without the first slash:
CommandParameter: file.ext.tmp
I'm able to successfully rename the file by supplying following absolute URI:
ftp.contoso.com/%2fusers/%2fname/file.ext.tmp
but I don't like this approach, since I would have to know the name of current user's directory. It can probably be done by using WebRequestMethods.Ftp.PrintWorkingDirectory, but it adds extra complexity (calling this method to retrieve directory name, then combining the paths to form proper URI).
What I don't understand is why the URI ftp.contoso.com/file.ext.tmp is good for upload and not for rename? Am I missing something here?
The project is set to .NET 4.0, coded in Visual Studio 2010.
Edit
Ok, I place code snippet.
Please note that ftp host, username and password should be filled out. For this sample to work - that is, produce an error - user directory must be different from root ("pwd"-command should return something different than "/")
class Program
{
private const string fileName = "test.ext";
private const string tempFileName = fileName + ".tmp";
private const string ftpHost = "127.0.0.1";
private const string ftpUserName = "anonymous";
private const string ftpPassword = "";
private const int bufferSize = 524288;
static void Main(string[] args)
{
try
{
string path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), fileName);
if (!File.Exists(path))
File.WriteAllText(path, "FTP RENAME SAMPLE");
string requestUri = "ftp://" + ftpHost + "/" + tempFileName;
//upload
FtpWebRequest uploadRequest = (FtpWebRequest)WebRequest.Create(requestUri);
uploadRequest.UseBinary = true;
uploadRequest.UsePassive = true;
uploadRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
uploadRequest.KeepAlive = true;
uploadRequest.Method = WebRequestMethods.Ftp.UploadFile;
Stream requestStream = null;
FileStream localFileStream = null;
localFileStream = File.OpenRead(path);
requestStream = uploadRequest.GetRequestStream();
byte[] buffer = new byte[bufferSize];
int readCount = localFileStream.Read(buffer, 0, bufferSize);
long bytesSentCounter = 0;
while (readCount > 0)
{
requestStream.Write(buffer, 0, readCount);
bytesSentCounter += readCount;
readCount = localFileStream.Read(buffer, 0, bufferSize);
System.Threading.Thread.Sleep(100);
}
localFileStream.Close();
requestStream.Close();
FtpWebResponse response = (FtpWebResponse)uploadRequest.GetResponse();
FtpStatusCode code = response.StatusCode;
string description = response.StatusDescription;
response.Close();
if (code == FtpStatusCode.ClosingData)
Console.WriteLine("File uploaded successfully");
//rename
FtpWebRequest renameRequest = (FtpWebRequest)WebRequest.Create(requestUri);
renameRequest.UseBinary = true;
renameRequest.UsePassive = true;
renameRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
renameRequest.KeepAlive = true;
renameRequest.Method = WebRequestMethods.Ftp.Rename;
renameRequest.RenameTo = fileName;
try
{
FtpWebResponse renameResponse = (FtpWebResponse)renameRequest.GetResponse();
Console.WriteLine("Rename OK, status code: {0}, rename status description: {1}", response.StatusCode, response.StatusDescription);
renameResponse.Close();
}
catch (WebException ex)
{
Console.WriteLine("Rename failed, status code: {0}, rename status description: {1}", ((FtpWebResponse)ex.Response).StatusCode,
((FtpWebResponse)ex.Response).StatusDescription);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
Console.ReadKey();
}
}
}

I have encountered a similar issue. The problem is that FtpWebRequest (incorrectly) prepends '/' to rename requests, as can be seen from this log (upload & rename):
URL:
http://127.0.0.1/Test.txt
FTP log:
STOR Test.txt.part
RNFR /Test.txt.part
RNTO /Test.txt
Please note that this problem occurs only when you are uploading to the root directory. If you changed the URL to http://127.0.0.1/path/Test.txt, then everything would work fine.
My solution to this problem is to use %2E (dot) as the path:
URL:
http://127.0.0.1/%2E/Test.txt
FTP log:
STOR ./Test.txt.part
RNFR ./Test.txt.part
RNTO ./Test.txt
You have to url-encode the dot, otherwise FtpWebRequest would simplify the path "/./" to "/".

C#
using System.Net;
using System.IO;
Rename Filename on FTP Server function
C#
private void RenameFileName(string currentFilename, string newFilename)
{
FTPSettings.IP = "DOMAIN NAME";
FTPSettings.UserID = "USER ID";
FTPSettings.Password = "PASSWORD";
FtpWebRequest reqFTP = null;
Stream ftpStream = null ;
try
{
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + FTPSettings.IP + "/" + currentFilename));
reqFTP.Method = WebRequestMethods.Ftp.Rename;
reqFTP.RenameTo = newFilename;
reqFTP.UseBinary = true;
reqFTP.Credentials = new NetworkCredential(FTPSettings.UserID, FTPSettings.Password);
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
ftpStream = response.GetResponseStream();
ftpStream.Close();
response.Close();
}
catch (Exception ex)
{
if (ftpStream != null)
{
ftpStream.Close();
ftpStream.Dispose();
}
throw new Exception(ex.Message.ToString());
}
}
public static class FTPSettings
{
public static string IP { get; set; }
public static string UserID { get; set; }
public static string Password { get; set; }
}

How to check if file exists on FTP before FtpWebRequest

I need to use FtpWebRequest to put a file in a FTP directory. Before the upload, I would first like to know if this file exists.
What method or property should I use to check if this file exists?

var request = (FtpWebRequest)WebRequest.Create
("ftp://ftp.domain.com/doesntexist.txt");
request.Credentials = new NetworkCredential("user", "pass");
request.Method = WebRequestMethods.Ftp.GetFileSize;
try
{
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
}
catch (WebException ex)
{
FtpWebResponse response = (FtpWebResponse)ex.Response;
if (response.StatusCode ==
FtpStatusCode.ActionNotTakenFileUnavailable)
{
//Does not exist
}
}
As a general rule it's a bad idea to use Exceptions for functionality in your code like this, however in this instance I believe it's a win for pragmatism. Calling list on the directory has the potential to be FAR more inefficient than using exceptions in this way.
If you're not, just be aware it's not good practice!
EDIT: "It works for me!"
This appears to work on most ftp servers but not all. Some servers require sending "TYPE I" before the SIZE command will work. One would have thought that the problem should be solved as follows:
request.UseBinary = true;
Unfortunately it is a by design limitation (big fat bug!) that unless FtpWebRequest is either downloading or uploading a file it will NOT send "TYPE I". See discussion and Microsoft response here.
I'd recommend using the following WebRequestMethod instead, this works for me on all servers I tested, even ones which would not return a file size.
WebRequestMethods.Ftp.GetDateTimestamp

Because
request.Method = WebRequestMethods.Ftp.GetFileSize
may fails in some case (550: SIZE not allowed in ASCII mode), you can just check Timestamp instead.
reqFTP.Credentials = new NetworkCredential(inf.LogOn, inf.Password);
reqFTP.UseBinary = true;
reqFTP.Method = WebRequestMethods.Ftp.GetDateTimestamp;

FtpWebRequest (nor any other class in .NET) does not have any explicit method to check a file existence on FTP server. You need to abuse a request like GetFileSize or GetDateTimestamp.
string url = "ftp://ftp.example.com/remote/path/file.txt";
WebRequest request = WebRequest.Create(url);
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.GetFileSize;
try
{
request.GetResponse();
Console.WriteLine("Exists");
}
catch (WebException e)
{
FtpWebResponse response = (FtpWebResponse)e.Response;
if (response.StatusCode == FtpStatusCode.ActionNotTakenFileUnavailable)
{
Console.WriteLine("Does not exist");
}
else
{
Console.WriteLine("Error: " + e.Message);
}
}
If you want a more straightforward code, use some 3rd party FTP library.
For example with WinSCP .NET assembly, you can use its Session.FileExists method:
SessionOptions sessionOptions = new SessionOptions {
Protocol = Protocol.Ftp,
HostName = "ftp.example.com",
UserName = "username",
Password = "password",
};
Session session = new Session();
session.Open(sessionOptions);
if (session.FileExists("/remote/path/file.txt"))
{
Console.WriteLine("Exists");
}
else
{
Console.WriteLine("Does not exist");
}
(I'm the author of WinSCP)

You can use WebRequestMethods.Ftp.ListDirectory to check if a file exist, no need for nasty try catch mechanism.
private static bool ExistFile(string remoteAddress)
{
int pos = remoteAddress.LastIndexOf('/');
string dirPath = remoteAddress.Substring(0, pos); // skip the filename only get the directory
NetworkCredential credentials = new NetworkCredential(FtpUser, FtpPass);
FtpWebRequest listRequest = (FtpWebRequest)WebRequest.Create(dirPath);
listRequest.Method = WebRequestMethods.Ftp.ListDirectory;
listRequest.Credentials = credentials;
using (FtpWebResponse listResponse = (FtpWebResponse)listRequest.GetResponse())
using (Stream listStream = listResponse.GetResponseStream())
using (StreamReader listReader = new StreamReader(listStream))
{
string fileToTest = Path.GetFileName(remoteAddress);
while (!listReader.EndOfStream)
{
string fileName = listReader.ReadLine();
fileName = Path.GetFileName(fileName);
if (fileToTest == fileName)
{
return true;
}
}
}
return false;
}
static void Main(string[] args)
{
bool existFile = ExistFile("ftp://123.456.789.12/test/config.json");
}

I use FTPStatusCode.FileActionOK to check if file exists...
then, in the "else" section, return false.