System.IO.File.Copy throws System.UnauthorizedAccessException - c#

I get an error when I try to copy a file from one location to another ONLY WHEN the file is already present in the destination. This happens inspite of setting the overwrite flag to true.
I am not getting any clue.
This is the code.
System.IO.File.Copy(source, destination, true);// goes fine as the destination file is not present
System.IO.File.Copy(source, destination, true);// Throws the exception
//"Access to the path 'C:\\Program Files (x86)\\testapp\\map\\sometext.txt' is denied."
Please guide.
Thanks
Sunil

This exception is covered in the documentation for File.Copy:
The caller does not have the required permission.
-or-
destFileName is read-only.
Check the attributes of the file after the first copy. Are the permissions what you expect? Do you need your program to run elevated (as administrator)?

If everything is fine, e.g. the file is not already open and path exists etc... this usually means that the user you run the program with is not allowed to do this action.
(simply file/folder permissions)
What kind of program is this? Is it a web application? If so, you would have to figure out which user is used to run the app pool and give permissions to that user.

Did you check the file is in read only mode or not ?

Related

c# window application system.data.oledb.oledbexception operation must use an updateable query

I have made a window application that works very well when i ran through but after creating its setup it is throwing below mentioned exception. I have try to give full access to the database file but still it is not working.
system.data.oledb.oledbexception operation must use an updateable.
query
i am using window 7 and installation folder is c:\program files\abc\ and access db is in same folder. Is this any issue of permissions? Please assist me to remove this exception.
There can be some permission issue just refer this Link
http://www.mikesdotnetting.com/Article/74/Solving-the-Operation-Must-Use-An-Updateable-Query-error
Make sure the ASPNET account (or whatever account is in use at the time) has
Change permissions to the directory where the .mdb file is located. Access
needs to write some temp and locking files during the operation.

C# - Access to mounted networkdrive

I have some networkshares mounted to my PC. I can see them in the Windows Explorer, with drive letters etc. If I try to read or write with c#, I always get a DirectoryNotFoundException.
The method to check if the directory exists
Directory.Exists(#"N:\test")
returns false (N:\ is the mounted share). If I open the path in the Explorer, the path exists.
Can you imagine, what the problem could be?
Thank you!
I just tested to see if this works when I run the application as administrator and it failed. So the reason is most probably because the user under which you execute the code doesn't have access to the path.
As you confirmed that you were indeed running the application with elevated privileges, you should follow the indications that are also suggested in this answer :https://stackoverflow.com/a/11268410/674700:
(...) open an administrative command prompt - where you have an
elevated token all the time - and create a matching drive mapping from
there (net use h: \server\share1). Since the standard user and the
elevated administrator have a common understanding of what "H:" drive
means, everything runs okay.
Well, I just try to assume why you can get this exception, here it is;
First of all, Directory.Exists() method works fine for network mounted drives. There could be a few more reason that why you get DirectoryNotFoundException in your work.
From MSDN;
The Exists method returns false if any error occurs while trying to
determine if the specified file exists. This can occur in situations
that raise exceptions such as passing a file name with invalid
characters or too many characters, a failing or missing disk, or if
the caller does not have permission to read the file.
I believe you have one of this but since we can't acces your computer, we can't know the real reason :)

Why is access to the path denied?

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)

'Access denied' to an xml file in windows application

In my .net windows application am using a xml file .
But after installing the application by creating setup, while I am running that 'Access Denied' to that xml file message is shown.
I am using System.IO.File methods for doing file operations.
If any body knows the solution pls share.
Write access to program directory has been more and more restricted (starting with XP/Vista) since that is a secruity risk!
I would suggest to have the "base version" of that file readonly in your program directory...
Upon start of your app you check whether it is present in ApplicationData or LocalApplicationData or CommonApplicationData - (to get the real path at runtime use Environment.GetFolderPath). If it is not there then copy it there - in those locations your application has write access by default with no need for Administrator rights.
Program Files folder has limited access and can be modified by Administrator account. I would suggest you to save your xml file in *C:\Users\YourPCName\AppData\Local\YourAppFolder* .
This way you will be able to access and modify the file
I had this problem once so I used Isolated Storage and that fixed my problem. It may or may not work for you depending on the nature of your situation, but here's a quick tutorial on how to use it:
http://www.codeproject.com/KB/dotnet/IsolatedStorage.aspx

Why am I only allowed to access this zip file in Debug mode?

I'm having a problem that doesn't make a lot of sense to me. I have an ASP.NET application that runs perfectly in Debug mode, but throws Access Denied errors when running normally. I've given the ASPNET account and the account the application impersonates Full Control rights on the files the webapp is calling (using the Process object).
I determined that the files throwing the error are in a zip file and that the process I'm running will not look for them anywhere but the zip file. But it seems that until I unzip the zip file, I can't set permissions on its contents. Does this make sense to anyone else? And does anyone know of a solution?
Set the permissions for CREATOR_OWNER on the folder it decompresses to.
What library do you use to access the zip file? Maybe you cannot open a single zip archive twice when to different threads try to extract a file from the archive at the same time?
Oh shoot, "Access Denied", not "Permission Denied". This one always catches me.
"Access Denied" is when you cannot open the file even though you have permissions, usually because somebody else already has it open.

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