I am downloading files from a client's SFTP.
When I do it from Filezilla it always succeeds in the standard way.
On the other side, when I do it from our app, that uses Tamir SharpSSH library for SFTP communication, periods constantly emerge when our all download attempts for a file fail.
I know the app works as that code has not been changes for several months and it worked much more often then it did not, but the periods keep reemerging when for the whole day or more all file downloads fail only for the app.
The exception I get is Tamir.SharpSsh.jsch.SftpException . Obviously not very helpful.
My guess is the client is doing modifications on their side, or changing permissions, as their side is not live yet, but with the exception message I do not know.
Does anybody has some suggestion? Where could I look for the solution? What should I test/try?
Thank you for the time!
The real message was 'No such file'. The reason was, a slash has been omitted for the root folder path, in one of our config files.
When you open the exception variable in VS Watch you will see all info properties from standard exception are null or simply set to 'Tamir.SharpSsh.jsch.SftpException'.
But, an additional property was apparently added to Tamir.SharpSsh.jsch.SftpException class - "message" and that is where the real message is stored, while Exception.Message is pretty often set to just "Tamir.SharpSsh.jsch.SftpException" .
The issue is the additional property is private and is only visible by VS Watch or similar.
Since our exception propagation mechanism is based on logging Exception.Message I was most of the time getting "Tamir.SharpSsh.jsch.SftpException"
I am developing a Windows Phone 8 application but am having a lot of issues with file access permission exceptions hindering the approval of my application when ever I try accessing files in the "local" folder (this only happens after the application has been signed by the WP store, not when deployed from Visual Studio). To solve this I have moved all file operations to IsolatedStorage and this seems to have fixed the problems.
I only have one problem left though. My application needs to make use of the file extension system to open external files and this seems to involve the file first being copied to the local folder where after I can then manually copy it into IsolatedStorage. I have no problem in implementing this but it seems that a file access permission exception also occurs once the system tries to copy the external file into the local folder.
The only way I think this can be solved is if I can direct the system to directly copy into IsolatedStorage but I cannot figure how to do this or if it is even possible. It seems as if though the SharedStorageAccessManager can only copy into a StorageFolder instance but I have no idea how to create one that is directed into IsolatedStorage, any ideas?
PS. Do you think that the Microsoft system might be signing my application with some incompetent certificate or something because there is not a hint of trouble when I deploy the application from Visual Studio, it only happens when Microsoft tests it or when I install it from the store using the Beta submission method.
Below is a screenshot of the catched exception being displayed in a messagebox upon trying to open a file from an email:
EDIT:
Just to make it even clearer, I do NOT need assistance in figuring out the normal practice of using a deep link uri to copy an external file into my application directory. I need help in either copying it directly into isolatedstorage or resolving the file access exception.
Listening for a file launch
When your app is launched to handle a particular file type, a deep link URI is used to take the user to your app. Within the URI, the FileTypeAssociation string designates that the source of the URI is a file association and the fileToken parameter contains the file token.
For example, the following code shows a deep link URI from a file association.
/FileTypeAssociation?fileToken=89819279-4fe0-4531-9f57-d633f0949a19
Upon launch, map the incoming deep link URI to an app page that can handle the file
// Get the file token from the URI
// (This is easiest done from a UriMapper that you implement based on UriMapperBase)
// ...
// Get the file name.
string incomingFileName = SharedStorageAccessManager.GetSharedFileName(fileID);
// You will then use the file name you got to copy it into your local folder with
// See: http://msdn.microsoft.com/en-us/library/windowsphone/develop/windows.phone.storage.sharedaccess.sharedstorageaccessmanager.copysharedfileasync(v=vs.105).aspx
SharedStorageAccessManager.CopySharedFileAsync(...)
I've inline the information on how to do this from MSDN http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj206987(v=vs.105).aspx
Read that documentation and it should be clear how to use the APIs as well as how to setup your URI mapper.
Good luck :)
Ok I figured it out. The "install" directory is actually restricted access but for some reason the Visual Studio signing process leaves the app with enough permissions to access this folder. The correct procedure of determining a relative directory is not to use "Directory.GetCurrentDirectory()" but rather to use "ApplicationData.Current.LocalFolder". Hope this helps!
I have an application in Visual Studio C# which includes saving into a text file, how can I have a .exe sent to another computer and not have an exception in saving?
I need to send a .exe file by email (Yes it's possible) and this application includes saving the state of the game. How can I send this .exe file and let the user be able to save in his computer please?
The problem is that when I send my application's executable file on another computer, I'm getting an exception in saving. Because on the other computer I don't have the text file which I'm saving the game.
I am saving here :
StreamWriter myFile = File.CreateText(Directory.GetCurrentDirectory()+"//ConnectFour.txt");
in the obj/Debug/ of the project..
Thanks for your help :)
Sending an executable should work just fine.
Make sure the other computer has the appropriate Microsoft .NET Framework installed.
Latest framework installer: MSDN
Also, make sure the path inwhich you're saving the file to exists on the remote computer. For example, if you're trying to save to the D:\ drive and it doesn't exist. You will get an exception.
Most likely current location is not writable by current user.
Using "current directory" is dangerous as you have no control over where application is launched from. It is very useful for command line utilities, but not so much for regular windowed applications. Use location that you know you can save files to - i.e. "My Documents".
var filePath = Path.Combine(
Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + "\\",
ConnectFour.txt");
using(var myFile = File.CreateText(filePAth))
{
// save data here.
}
The problem when sending executables by email are the anti-virus-scanners. Some of them refuse e-mails containing executables. Others accept the mails but delete the attachment.
The solution consists in hiding the executable. This can be done by zipping the executable and sending the zip-file.
Often this is enough to solve the problem but some anti-virus-scanners are very smart and even recognize executables within the zip-attachment. The solution here is to encrypt the zip-file with a password. I often just use the password "pwd" and mention it in the e-mail text. The anti-viruses are not (yet) smart enough to understand this text.
UPDATE
Now I understand your problem. It has nothing to do with sending the executable.
An application can determine from which directory it has been started like this
string dir = System.IO.Path.GetDirectoryName(
System.Windows.Forms.Application.ExecutablePath
);
An alternative is (if you don't have a reference to WinForms):
string dir = System.IO.Path.GetDirectoryName(
System.Reflection.Assembly.GetEntryAssembly().Location
);
You probably do not have sufficient privileges to save the file on the remote machine. If you give us more information on the exact exception that is being thrown (type of exception, message, stack trace, etc) you will get a more accurate answer.
At first I thought I'm facing a very simple task. But now I realized it doesn't work as I imagined, so now I hope you people can help me out, because I'm pretty much stuck at the moment.
My scenario is this (on a Windows 2008 R2 Server):
A file gets uploaded 3 times per day to a FTP directory. The filename is always the same, which means the existing file gets overwritten every time.
I have programed a simple C# service which is watching the FTP upload directory, I'm using the FileSystemWatcher class for this.
The upload of the file takes a few minutes, so once the File Watcher registers a change, I'm periodically trying to open the file, to see if the file is still being uploaded (or locked)
Once the file isn't locked anymore, I try to move the file over to my IIS Virtual Directory. I have to delete the old file first, and then move the new file over. This is where my problem starts. The file seems to be always locked by IIS (the w3wp.exe process).
After some research, I found out that I have to kill the process which is locking the file (w3wp.exe in this case). In order to do this, I have created a new application pool and converted the virtual directory into an application. Now my directory is running under a seperate w3wp.exe process, which I supposedly can safely kill and move the new file over there.
Now I just need to find the proper w3wp.exe process (there are 3 w3wp.exe processes running in total, each running under a seperate application pool) which has the lock on my target file. But this seems to be an almost impossible task in C#. I found many questions here on SO regarding "Finding process which locked a specific file", but none of the answers helped me.
Process Explorer for example is exactly telling me which process is locking my file.
The next thing I don't understand is, that I can delete the target file through Windows Explorer without any problem. Just my C# application gets the "File is being used by another process" error. I wonder what's the difference here...
Here are the most notable questions on SO regarding locked files and C#:
Win32: How to get the process/thread that owns a mutex?
^^
The example code here does actually work, but this outputs the open handle IDs for every active process. I just can't figure out how to search for a specific filename, or at least resolve the handle ID to a filename. This WinAPI stuff is way above my head.
Using C#, how does one figure out what process locked a file?
^^
The example code here is exactly what I need, but unfortunately I can't get it to work. It is always throwing an "AccessViolationException" which I can't figure out, since the sample code is making extensive use of WinAPI calls.
Simple task, impossible to do? I appreciate any help.
EDIT
Here are some relevant parts of my server code:
Helper function to detect if a file is locked:
private bool FileReadable(string file, int timeOutSeconds)
{
DateTime timeOut = DateTime.Now.AddSeconds(timeOutSeconds);
while (DateTime.Now < timeOut)
{
try
{
if (File.Exists(file))
{
using (FileStream fs = File.Open(file, FileMode.Open, FileAccess.Read, FileShare.None))
{
return true;
}
}
return false;
}
catch (Exception)
{
Thread.Sleep(500);
}
}
m_log.LogLogic(0, "FileReadable", "Timeout after [{0}] seconds trying to open the file {1}", timeOutSeconds, file);
return false;
}
And this is the code in my FileSystemWatcher event, which is monitoring the FTP upload directory. filepath is the newly uploaded file, targetfilepath is the target file in my IIS directory.
// here I'm waiting for the newly uploaded file to be ready
if (FileReadable(filepath, FWConfig.TimeOut))
{
// move uploaded file to IIS virtual directory
string targetfilepath = Path.Combine(FWConfig.TargetPath, FWConfig.TargetFileName);
if(File.Exists(targetfilepath))
{
m_log.LogLogic(4, "ProcessFile", "Trying to delete old file first: [{0}]", targetfilepath);
// targetfilepath is the full path to my file in my IIS directory
// always fails because file is always locked my w3wp.exe :-(
if(FileReadable(targetfilepath, FWConfig.TimeOut))
File.Delete(targetfilepath);
}
File.Move(filepath, targetfilepath);
}
EDIT2:
Killing the w3wp.exe process while clients are downloading the file would be no problem for us. I'm just having a hard time finding the right w3wp.exe process which is locking the file.
Also, my client application, which is downloading the file on the clients, is checking the HTTP HEAD for the Last-Modified date. The client is checking the date every 10 minutes. So it is possible that the file is being locked by IIS because there are clients continously checking the HTTP HEAD for the file. Nonetheless, I don't understand why I can manually delete/rename/move the file through windows explorer without any problems. Why does this work, and why does my application get a "Locked by another process" exception?
One problem I've run into is that a file exists while it is still being written, which means it would be locked as well. If your FileReadable() function were called at this time, it would return false.
My solution was to, in the proc which writes the file, write the file to, say, OUTPUT1.TXT, and then after it is fully written and the FileStream closed, rename it to OUTPUT2.TXT. This way, the existence of OUTPUT2.TXT indicates that the file is written and (hopefully) unlocked. Simply check for OUTPUT2.TXT in your FileReadable() loop.
Everybody say...
"Do it a better way"
Nobody say how!!!
Here's how. Because you mentioned 'My Client Application,' there is a key opportunity here that you would not have if you didn't have control over the apps reading the file.
Just use new filenames each time.
You have control of the program reading and writing the files. Put an incrementing # in the filesnames, have the client pick the biggest # (Actually the latest date, then your numbers can wrap around). Have the writer program clean up old files if it can; if not, they won't hurt anything. IIS will eventually let go of them. If not, just open up explorer every week and do it yourself!
Other keys that make this work are the low frequency of updates (files won't build up too bad), and the fact that the FTP+webserver are on the same drive (Otherwise the MOVE is not atomic and clients could get a half-copied file. Solution if FTP drive is different would be to copy to a temp drive on the webserver then move).
but what if you can't change the client or it has to read just one name?
Front-end it with a script. Have the client hit an ASPX that sets the right HTTP headers and has the 'pick the right file' logic, and spits out the file contents. This is a very popular trick pages use to write images stored on a database out to the browser, while the img tag appears to read from a file. (google along that lines for sample code).
sounds like a hack, it's not. Modern lockless memory cache systems do a similar thing. It is impossible for a lock or corruption to occur; until the 'write' is complete, readers see the old version.
plus, it's simple, everybody from a script kiddie to a punchcard vetern will know exactly what you're up to. Go low-tech!
You're troubleshooting a symptom of the problem not a fix for the root cause. If you want to go down that path here is the code to kill processes http://www.codeproject.com/Articles/20284/My-TaskManager - but the better idea would be to do it properly and work out whats wrong. I suggest in the Catch Exception of FileReadable:
catch (Exception ex) {
if (ex is IOException && IsFileLocked(ex)) {
//Confirm the code see's it as a FileLocked issue, not some other exception
//its not safe to unlock files used by other processes, because the other process is likely reading/writing it.
}
}
private static bool IsFileLocked(Exception exception)
{
int errorCode = Marshal.GetHRForException(exception) & ((1 << 16) - 1);
return errorCode == 32 || errorCode == 33;
}
Turn off any Anti-Virus software and re-test
Increase the polling timeout duration to see if its just a timing thing
Check the FTP logfile and see the status for the disconnected client and compare the status code with the ones here.
I don't see in your sample code where you are closing your file stream. Keeping the file stream open will keep a lock on the file. It would be a good idea to close the stream. You probably don't want to be killing your w3wp.exe process, as others here have mentioned.
restarting IIS can unlock the file taken by w3wp.exe.
cmd (run as administrator) -> iisreset /stop -> update/delete file in
windows explorer -> iisreset /start
I am having a problem where I am trying to delete my file but I get an exception.
if (result == "Success")
{
if (FileUpload.HasFile)
{
try
{
File.Delete(Request.PhysicalApplicationPath + app_settings.login_images + txtUploadStatus.Text);
string filename = Path.GetFileName(btnFileUpload.FileName);
btnFileUpload.SaveAs(Request.PhysicalApplicationPath + app_settings.login_images + filename);
}
catch (Exception ex)
{
Message(ex.ToString());
}
}
}
Also I should note that the folder I am trying to delete from has full control to network services.
The full exception message is:
System.UnauthorizedAccessException: Access to the path 'C:\Users\gowdyn\Documents\Visual Studio 2008\Projects\hybrid\hybrid\temp_loginimages\enviromental.jpg' is denied. at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) at System.IO.File.Delete(String path) at hybrid.User_Controls.Imgloader_Add_Edit_Tbl.btnUpdate_Click(Object sender, EventArgs e) in C:\Users\gowdyn\Documents\Visual Studio 2008\Projects\hybrid\hybrid\User_Controls\Imgloader_Add_Edit_Tbl.ascx.cs:line 242
Any ideas?
According to File.Delete Method...
An UnauthorizedAccessException means one of 4 things:
The caller does not have the required permission.
The file is an executable file that is in use.
Path is a directory.
Path specified a read-only file.
I also had the problem, hence me stumbling on this post. I added the following line of code before and after a Copy / Delete.
Delete
File.SetAttributes(file, FileAttributes.Normal);
File.Delete(file);
Copy
File.Copy(file, dest, true);
File.SetAttributes(dest, FileAttributes.Normal);
This is an old issue, but I ran into it while searching. Turns out that I was missing the actual filename component in the save path for SaveAs...
string uploadPath = Server.MapPath("~/uploads");
file.SaveAs(uploadPath); // BAD
file.SaveAs(Path.Combine(uploadPath, file.FileName)); // GOOD
When a user tries to connect to your Web site, IIS assigns the connection to the IUSER_ComputerName account, where ComputerName is the name of the server on which IIS is running. By default, the IUSER_ComputerName account is a member of the Guests group. This group has security restrictions. Try to grand access to IUSER_ComputerName to that folder
Here is very good described answer about IIS security
Hope this helps
I got the error because I didn't realize that the destination should be a file. I had a folder as the second parameter (which works in cmd). and I got Unhandled Exception: System.UnauthorizedAccessException: Access to the path is denied. because C# File.Move wants a file there, not just for the first parameter, but for the second too, and so if you put a directory as second parameter, it's trying to write a file like c:\crp when you have a directory called c:\crp.
this would be incorrect File.Move(args[0],"c:\\crp");
So, this would be correct File.Move(args[0],"c:\\crp\\a.a");
The same goes for File.Copy
Right-click on Visual studio and click Run as Administrator
Thanks for +1
If this is an IIS website that is having the problem, check the Identity property of the advanced settings for the application pool that the site or application uses. You may find that it is set to ApplicationPoolIdentity, and in that case then this is the user that will have to have access to the path.
Or you can go old style and simply set the Identity to Network Service, and give the Network Service user access to the path.
You need to modify the privileges of the folder you're trying to delete from/save to. Right-click on the containing folder and use the Security tab to permit modify rights for the user your application runs under.
An UnauthorizedAccessException exception is thrown when the operating system denies access because of an I/O error or a security error.
If you are attempting to access a file or registry key, make sure it is not read-only.
I have also faced this issue when my window service started throwing the exception
System.UnauthorizedAccessException: Access to the path "C:\\Order\\Media
44aa4857-3bac-4a18-a307-820450361662.mp4" is denied.
So as a solution, I checked the user account associated with my service, as shown in below screen capture
So in my case it was NETWORK SERVICE
And then went to the folder properties to check if the associated user account also exists under their permission tab. It was missing in my case and when I added it and it fixed my issue.
For more information please check the below screen capture
same issue for me too,
I was pointing the folder instead of file.
so make sure in path, give path+filename
System.IO.File.WriteAllBytes("path", bytearray);
The exception that is thrown when the operating system denies access
because of an I/O error or a specific type of security error.
I hit the same thing. Check to ensure that the file is NOT HIDDEN.
Check your files properties. If the read-only is checked, uncheck it. This was my personal issue with the UnauthorizedAccessException.
I got this error and solved it in just a moment. Don't know why all of my folders are read-only，I cancelled the read-only and apply it. However, it is still read-only. So I moved the file into the root folder, it works - so weird.
I was facing this error because
Sometimes when I Combine the path with File Name and FileName = ""
It become Path Directory not a file which is a problem as mentioned above
so you must check for FileName like this
if(itemUri!="")
File.Delete(Path.Combine(RemoteDirectoryPath, itemUri));
I was trying to use System.IO.File.OpenWrite(path)
and it did not work because I was only passing OpenWrite() a path to a directory, but it requires a path all the way to the file you want to write. So a full path including the filename.extension at the end needs to be passed into OpenWrite to avoid UnauthorizedAccessException
In my case the problem was Norton. My in-house program doesn't have the proper digital signature and when it tried to delete a file it gave the UnauthorizedAccessException.
If it give you a notification, you can handle it from there. In my case it didn't give a notification that I noticed. So here's how to keep Norton from blocking the program.
Open Norton
Click the down arrow
Click History
Find activity by program
Click More Options
Click Exclude Process
To solve this problem, I follow the Scot Hanselman approach at Debugging System.UnauthorizedAccessException (often followed by: Access to the path is denied) article, the code with example is bellow:
class Program
{
static void Main(string[] args)
{
var path = "c:\\temp\\notfound.txt";
try
{
File.Delete(path);
}
catch (UnauthorizedAccessException)
{
FileAttributes attributes = File.GetAttributes(path);
if ((attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)
{
attributes &= ~FileAttributes.ReadOnly;
File.SetAttributes(path, attributes);
File.Delete(path);
}
else
{
throw;
}
}
}
}
I had the same problem on a newly moved website on a shared server. Solved through the web host panel (DotNetPanel) setting true the "allow write permissions". So if you are in a shared server before reviewing all code worth taking a look at the server configuration and could save you a lot of time.
Be aware that if you are trying to reach a shared folder path from your code, you dont only need to give the proper permissions to the physicial folder thru the security tab. You also need to "share" the folder with the corresponding app pool user thru the Share Tab
I had the exact error when deleting a file. It was a Windows Service running under a Service Account which was unable to delete a .pdf document from a Shared Folder even though it had Full Control of the folder.
What worked for me was navigating to the Security tab of the Shared Folder > Advanced > Share > Add.
I then added the service account to the administrators group, applied the changes and the service account was then able to perform all operations on all files within that folder.
For those trying to make a UWP (Universal Windows) application, file permissions are much more restricted, and in general is deny by default. It also supersedes the system user permissions. You will basically only have access to files in either
Your install location
Your AppData location
Files selected through the File or Folder picker
Locations requested in your App Manifest
You can read more here for details => https://learn.microsoft.com/en-us/windows/uwp/files/file-access-permissions
If you're using BitDefender there's a good chance its Safe Files feature blocked your operation. This is a form of Ransomware protection that comes with some of its more advanced versions.
Make sure to grant your application access in BitDefender and try again.
Some more details can be found in this BitDefender support page.
In my case it was my AVG anti-virus that triggered the exception.
I added my VS Projects directory to the "Allowed" list. And I had to add the executable to the AVG exceptions list after I copied the .exe to my App directory.
I've had the same problem and I've managed to get it working by changing the partition on which the file will be saved. So, on line 5 I've changed #"C:\" to be #"D:\" and that resolved the problem.
static void SaveVideoToDisk(string link)
{
var youTube = YouTube.Default; // starting point for YouTube actions
var video = youTube.GetVideo(link); // gets a Video object with info about the video
File.WriteAllBytes(#"D:\" + video.FullName, video.GetBytes());
}
After migrating from Visual Studio 2017 to Visual Studio 2019 I faced two exceptions with two of my applications which run properly under Visual Studio 2017:
System.UnauthorizedAccessException
System.ArgumentException
It turned out that I had to add the executables of the two applications to the allowed apps of Avast Antivirus.
I too faced the same problem when trying to do this after deployment at server:
dirPath = Server.MapPath(".") + "\\website\\" + strUserName;
if (!Directory.Exists(dirPath))
{
DirectoryInfo DI = Directory.CreateDirectory(dirPath);
}
string filePath = Server.MapPath(".") + "\\Website\\default.aspx";
File.Copy(filePath, dirPath + "\\default.aspx", true);
File.SetAttributes(dirPath + "\\default.aspx", FileAttributes.Normal);
I granted permission in IIS to other group including administrator and my problem got solved.
In my particular case I was repeatedly creating and deleting 10000 folders. It seems to me that the problem was in that although the method Directory.Delete(path, true) returns, the underling OS mechanism may still be deleting the files from the disk. And when I am starting to create new folders immediately after deletion of old ones, some of them are still locked because they are not completely deleted yet. And I am getting System.UnauthorizedAccessException: "Access to the path is denied".
Using Thread.Sleep(5000) after Directory.Delete(path, true) solves that problem. I absolutely agree that this is not safe, and I am not encouraging anyone to use it. I would love to here a better approach to solve this problem to improve my answer. Now I am just giving an idea why this exception may happen.
class Program
{
private static int numFolders = 10000;
private static string rootDirectory = "C:\\1";
static void Main(string[] args)
{
if (Directory.Exists(rootDirectory))
{
Directory.Delete(rootDirectory, true);
Thread.Sleep(5000);
}
Stopwatch sw = Stopwatch.StartNew();
CreateFolder();
long time = sw.ElapsedMilliseconds;
Console.WriteLine(time);
Console.ReadLine();
}
private static void CreateFolder()
{
var one = Directory.CreateDirectory(rootDirectory);
for (int i = 1; i <= numFolders; i++)
{
one.CreateSubdirectory(i.ToString());
}
}
}
First just check the path if the colon(:) character is missing or not after the drive letter. If colon is not missing then you can check if access/write permission is granted for that path.
I had the same issue and i was only missing the colon, permission and everything else was fine.
C:\folderpath
will work fine but,
C\folderpath .........(missing colon)
will give you access denial error.
I also ran into this post as dealing with the same issue. Looks like the file is in use and hence not able to write to it.
Though not able to figure it out, which process is using it. Signed out the other user who was logged in in that box, dont see any users who is holding it.
Any quick tips regarding on how to find the same.
Thanks,
Lakshay (developer)