I have some code that I wrote to basically clear out the directory every time the program runs through this point. I didn't want to bother enumerating files. If this is a bad way to do this, please tell me.
My main question, however, is about how to deal with the following: one of the files in the folder appears to be in use when it is most certainly not. The program runs on a ButtonClick event, and it exploded the first four or five times, but it worked after I confirmed that nobody was using the file on the server. There is only one person besides myself that would have been using it, and he confirmed that there was nothing running on his side that would be touching the file. Any ideas for what would cause this error/how to avoid it/how to handle it?
I am also having trouble reproducing the error...
string directory = #"\\server\directory\folder\";
DirectoryInfo di = new DirectoryInfo(directory);
if (di.Exists)
di.Delete(true);
Directory.CreateDirectory(directory);
If you are using Windows XP, this may help : http://msdn.microsoft.com/en-us/library/dd997370.aspx#remove_open_handles
Just an extract from the top of this page :
"If you are running Windows XP or earlier, a delete operation on a file or directory that follows an enumeration could fail if there is an open handle that remains on one of the enumerated directories or files."
You may also use a software like Unlocker to identify the process locking your file.
If the file is in use, then someone is most certainly using it. :)
If you can access the server the files reside on, you can use a tool such as Process Explorer to find out which process has opened the file.
Related
I'm getting a very intermittent "directory not empty" error trying to delete a directory from c# code but when I look, the directory seems to be empty.
The actual scenario is this: process A invokes process B using a synchronous .Net remoting call, process B deletes the files from the directory and then returns to process A which deletes the directory itself. The disk is a locally attached NTFS Disk (probably SATA).
I'm wondering if there's a possible race Condition with NTFS when you have two processes cooperating in this way, where process B's delete calls have not been completely flushed to the file system?
Of course the more obvious answer is that the directory was genuinely not empty at the time and something else emptied it before I looked at it, but I don't see how this could happen in my current application because there's no other process which would delete the files.
Sure, deleting directories is a perilous adventure on a multi-tasking operating system. You always have the risk that another process has a file opened. Failure to delete the directory in your scenario has two primary reasons:
Particularly trouble-some are the kind of processes that opens the file in a way that does not prevent you from deleting the file but still makes deleting the directory fail with this error. Search indexers and anti-malware fit this category. They'll open the file with delete sharing, FileShare.Delete in a .NET program. Deleting the file works fine. But the file won't disappear until they close the file handle. So you can't delete the directory until they do.
Very hard to diagnose is a process that has the directory selected as its current working directory. Environment.CurrentDirectory in a .NET program. Explorer tends to trigger this, just looking at the directory is enough to prevent it from getting deleted.
These mishaps occur totally outside of your control. You will need to deal with them, catching the exception is required. Little you can do by try again later, there is however no upper limit on how long you'll have to wait. Renaming the directory and giving it a "trash" name is a good strategy. Note how the recycle bin in Windows essentially follows this scenario, good for more than just recycling :)
I have read a similar post, but i just cant figure out the problem.
I have changed the windows permissions and changed routes.
When i try to save a file it throws me the exception:
Access to the path **** denied.
string route="D:\\";
FileStream fs = new FileStream(route, FileMode.Create); <--here is the problem
StreamWriter write = new StreamWriter(fs);
patient person = new patient();
patient.name = textBox1.Text;
patient.name2 = textBox2.Text;
You are trying to create a FileStream object for a directory (folder). Specify a file name (e.g. #"D:\test.txt") and the error will go away.
By the way, I would suggest that you use the StreamWriter constructor that takes an Encoding as its second parameter, because otherwise you might be in for an unpleasant surprise when trying to read the saved file later (using StreamReader).
Did you try specifing some file name?
eg:
string route="D:\\somefilename.txt";
tl;dr version: Make sure you are not trying to open a file marked in the file system as Read-Only in Read/Write mode.
I have come across this error in my travels trying to read in an XML file.
I have found that in some circumstances (detailed below) this error would be generated for a file even though the path and file name are correct.
File details:
The path and file name are valid, the file exists
Both the service account and the logged in user have Full Control permissions to the file and the full path
The file is marked as Read-Only
It is running on Windows Server 2008 R2
The path to the file was using local drive letters, not UNC path
When trying to read the file programmatically, the following behavior was observed while running the exact same code:
When running as the logged in user, the file is read with no error
When running as the service account, trying to read the file generates the Access Is Denied error with no details
In order to fix this, I had to change the method call from the default (Opening as RW) to opening the file as RO. Once I made that one change, it stopped throwing an error.
I had this issue for longer than I would like to admit.
I simply just needed to run VS as an administrator, rookie mistake on my part...
Hope this helps someone <3
If your problem persist with all those answers, try to change the file attribute to:
File.SetAttributes(yourfile, FileAttributes.Normal);
You do not have permissions to access the file.
Please be sure whether you can access the file in that drive.
string route= #"E:\Sample.text";
FileStream fs = new FileStream(route, FileMode.Create);
You have to provide the file name to create.
Please try this, now you can create.
TLDR : On my end, it had something to do with AVAST ! => Whitelist your application.
All of a sudden, I also got this UnauthorizedAccessException problem in the windows WPF program I'm writing. None of the solutions worked - except I couldn't figure out how to elevate my application to full privileges (not using VS) while at the same time, being already on the administrator account, I didn't feel the need to dig that deep in permission concerns.
The files are image files (jpg, psd, webp, etc.) I wasn't trying to open/write a directory, it has always been a valid path to a file, and I needed to write to the file, FileAccess.ReadWrite was inevitable. The files (and any of their parent directory) were not readonly (I even checked by code prior calling new FileStream(path, mode, access, share) via FileInfo.IsReadOnly) - so what happenned all of a sudden ???
Thinking about : I had an had drive crash, so I unpacked a backup of my solution code from another drive. In the meantime, I added codes in my application to PInvoke APIs to directly read hard drive sectors physical bytes as well as USB plug/unplug monitoring.
I started to get the Exception when I added those, but even though I temporarly removed the related codes from the application, I still got the UnauthorizedAccessException.
Then I remembered one thing I've done long ago, a painstaking similar issue where I wanted my application to communicate sensible data via Wifi, which was to add the executable among AVAST exceptions, and the assembly directory aswell (My app was already among the authorized apps through firewall)
Just did it for my application in AVAST settings, AND THE EXCEPTION IS GONE !!! Two whole days I'm lurking StackOverflow and the web to get moving on, FINALLY !
Details : I can't pinpoint exactly what AVAST didn't like in my application as the only changes I made :
Retrieved then launched the backup code - it worked like a charm, files (images) opens/write without problems (3 days ago)
Added USB detection (3 days ago - Just tested the code, didn't tried to open an image)
Added PInvoke physical drive direct read (2 days ago - FileStream, and the logic to define where/how to scan the damaged drive - Just tested the code, didn't tried to open an image)
Added image format detection starting from Jpg/Jfif.. 2 days ago, got the exception upon testing the code.
While searching for solutions, added an Image Gallery WPF UserControl to diplay pictures based on their signature and check which files gives the exception : almost all of them (some files opens/write okay - why ???)
Tried everything I've found on SO (since the last 2 days) until I opened AVAST settings and whitelist my application.
... now I can move on into adding a bunch of file signatures to retrieve as many datas as I could.
If this may help those who like me, aren't failing on the "I'm passing a directory path instead that of a file", yet, have no time to learn exactly why antiviruses think our own code is a malware.
Just Using the below worked for me on OSX.
var path = "TempForTest";
This question already has answers here:
Why does rename a loaded .net assembly work?
(3 answers)
Closed 5 years ago.
We are trying to push updates to multiple servers at once and my manager has found that it is possible to rename running .exe file. Using that knowledge he wants to rename a running exe and copy over a new version of said exe such that anyone running their in memory copy of foo.exe are fine and anybody who opens a shortcut pointing to foo.exe will get a new copy with updates applied.
I guess I need to clarify, He doesn't expect the old copy to magically update, he just expects them to keep running the old copy until they open the exe again, in which case it will then open the new one that has the name of the old one.
It sometimes throws an exception that the file is in use on his program but if he tries renaming it in a loop it will eventually succeed. On my machine I have yet to be able to get it to work even in a loop.
My first and main question is this: Is it ever acceptable to do this. Should renaming a running executable ever be a valid scenario?
Secondly, if it is a valid scenario then how could one reliably do this? Our current thoughts are try a bunch of times using File.Move (C#) to do a rename and if it doesn't work then write out to an error log so it can be handled manually.
An airplane mechanic and a surgeon meet in a bar. The mechanic says "you know, we have basically the same job. We take broken stuff out and put new, better parts in." The surgeon says "yeah, but you don't have to keep the plane flying as you're making the repairs!"
Trying to update an application by moving files while the application is running seems about as dangerous as trying to fix an airplane in flight. Possible? Sure. Greatly increased risk of catestrophic crash? Yep.
If the application you are updating is a managed application, consider using ClickOnce Deployment. That way, the next time someone runs the application, if there is a new version available it will be copied down and installed automatically. That's much more safe and pleasant than trying to mess with an application while its still running.
No, this is not acceptable. Do not do this. This is not a valid deployment mechanism. This should have been yours or his first clue:
It sometimes throws an exception that the file is in use on his program but if he tries renaming it in a loop it will eventually succeed.
And it won't work, anyway. His theory is quite wrong:
Using that knowledge he wants to rename a running exe and copy over a new version of said exe such that anyone running their in memory copy of foo.exe are fine and anybody who opens a shortcut pointing to foo.exe will get a new copy with updates applied.
Specifically, the copy in memory will not be automatically replaced with the new executable just because it has the same name. The reason that you're allowed to rename the executable in the first place is because the operating system is not using the file name to find the application. The original executable will still be loaded, and it will remain loaded until you explicitly unload it and load the new, modified executable.
Notice how even modern web browsers like Chrome and Firefox with their super fancy automatic, in the background, no one ever notices that they exist, updaters still have to close and relaunch the application in order to apply the updates.
Don't worry about shooting the messenger here. It's more likely that your customers and your tech support department will shoot you first.
See number 1.
In our organization, we solved the problem of Updates by having two release folders say EXE_A and EXE_B. We also have a release folder called EXE which only has links ALL of which points to either to EXE_A or EXE_B from which the user runs the applications.
When we publish a new version of the program, we publish it to the folder that is not referenced in the links and then update the links (EXE). In this way, you do not get into exceptions that users are holding the application / assemblies. Also if a user wants to run the updated version, all he need to do is close / re-execute the link in EXE folder.
If you use Windows Vista/Server2k8 or newer you could use mklink to create a symbolic link to the folder containing your application and start the application out of the "symblic linked folder" and then at the update create a new folder, e.g. "AppV2" and change the SymLink to that folder, so the next time the user restarts the application he starts it out of the new folder without noticing.
Renaming open files is ALWAYS a bad choice!
But in general I would think of a better deployment strategy anyway, because if you need to use such "hacks" it is always a messy situation. I don't know your application, but maybee ClickOnce would be a point to start, because you can configure it to check for updates on every start...
If i make the call File myFile = new File('myfile.txt'); where is does this get saved to?
It's relative to the process's current directory. What that is will depend on how your application has been started, and what else you've done - for example, some things like the choose file dialog can change the current working directory.
EDIT: If you're after a temporary file, Path.GetTempFileName() is probably what you're after. You can get the temp folder with Path.GetTempPath().
That won't compile.
EDIT: However, if you're after where creating a text file using StreamWriter or File.Create("text.txt"), etc, then I defer to the other answers above; where it will be where the application is running from. Be aware as others mentioned that if you're working out of debug it will be in the debug folder, etc.
NORMALLY it gets saved to the same directory the executable is running in. I've seen exceptions. (I can't remember the specifics, but it threw me for a loop. I seem to recall it being when it's run as a scheduled task, or if it's run from a shortcut.
The only reliable way to know where it is going to save if you are using the code snippet you provided is to check the value of System.Environment.CurrentDirectory. Better yet, explicitly state the path where you want it to save.
Edit - added
I know this is a bit late in modifying this question, but I found a better answer to the problem of ensuring that you always save the file to the correct location, relative to the executable. The accepted answer there is worth up-votes, and is probably relevant to your question.
See here: Should I use AppDomain.CurrentDomain.BaseDirectory or System.Environment.CurrentDirectory?
Unable to copy file "obj\Debug\FootballLeague.exe" to "bin\Debug\FootballLeague.exe". The process cannot access the file 'bin\Debug\FootballLeague.exe' because it is being used by another process.
I got this problem and I couldnt find any another process.Other c# programmes are working properly.I changed the place which I haved saved first time, but I couldnt get any clue to find the error.
Chances are the other process is FootballLeague.exe - are you sure you aren't still running it?
Another alternative is to use Process Explorer to find out what's got a handle on the file.
If your FootballLeague.exe has been launched and is still running, it is the process that is locking the file.
Do you have a virus scanner turned on? They tend to open files for exclusive access at just the wrong time. I would advise that you turn off real-time scanning in your project directory at a minimum.
Other than that, you'll want to use something like Process Explorer to find out who actually has the file open.