Develop Reference

Writing a CSV log file

I have a Winforms program that needs to log data points into a .CSV file. It's fairly simple, date/time and a double (the data), and go to the next line.
Here's what I have so far (not working, I get an error saying the file is busy/already open - however, it's empty)
if (!Directory.Exists(SavePath.Text + "\\LOG"))
Directory.CreateDirectory(SavePath.Text + "\\LOG");
string LogFileName = SavePath.Text + "\\LOG\\Seeing-Log-" + TimeNow.ToString("yyyy-MM-dd") + ".csv";
if (!File.Exists(LogFileName))
File.Create(LogFileName);
string LogString = TimeNow.ToString("yyyy-MM-dd-_HH-mm-ss") + "," + FWHM_Value.ToString("F:");
File.AppendAllText(LogFileName, LogString + Environment.NewLine);
It's that last line that generates the error.
Any idea what I am doing wrong?
thanks
Steve

File.Create returns an open FileStream to the file that's just been created. Either change your code to work with FileStream in both the non-existent and existent file cases, or just close the file after creating it:
if (!File.Exists(LogFileName))
File.Create(LogFileName).Close();
But, of course, if you check the documentation for AppendAllText:
Appends the specified stringto the file, creating the file if it does not already exist.
You'll realise that the above two lines are completely redundant anyway and can be removed:
if (!Directory.Exists(SavePath.Text + "\\LOG"))
Directory.CreateDirectory(SavePath.Text + "\\LOG");
string LogString = TimeNow.ToString("yyyy-MM-dd-_HH-mm-ss") + "," + FWHM_Value.ToString("F:");
File.AppendAllText(LogFileName, LogString + Environment.NewLine);

You can even use the free looging tools. Here is one 'log4net'
You can also write the csv file using this. I am assuming currently you are not using logging tool. it will work for you without any code for implementation .
http://element533.blogspot.in/2010/05/writing-to-csv-using-log4net.html
Have a great day!!

Replace
File.Create(LogFileName);
with
File.Create(LogFileName).Close();
see this to create empty file.

The file is locked when you create it. Just update your code to this:
File.Create(LogFileName).Close();

.Net Application logging

Hello all I have a scenario where i have one winform app as server and infinite number of winform apps as clients
basically each client connects to server and sends a string to server , server than do some calculations and return string back to client, but server have to connect to another server for calculation of that string and in response from that second server our main server stores the response in a string variable and after some specific time intervals it shows that string variable in a textbox but this string gets bigger and bigger after each calculation and hence my server some times starts consuming 1gb memory in task manager and 40% of my cpu usage , and when i removed the string variable my server was running on 45mb of memory and 0-4% of cpu usage i am using string variable like this
string Serverlog += datafetched + "cl"
i have also tried a string builder object but result is same so can any one help me to sort out things ( how can i save logs without consuming to much memory ) and one thing more logs will not be maitained in any file they are only for showing them into textbox

Best solution is to store your logging somewhere, database / file / winlogging / other
What kind of app are you running on the clients? Be aware that u use the AppendText function of the textbox. So dont use:
Textbox.Text += "additional info"
but use
Textbox.AppendText(teTonenTekst + Environment.NewLine);

While logging to a file is best, you mentioned you do not want that.
For UI based logging, I usually avoid a TextBox, and instead use a ListView or DataGridView with hidden gridlines. That way it is easy to truncate the amount of values to a limit, keeping only recent data in the control.
It is also easier to color code different types of logging data.

You can write the text in to the file or MSMQ or Telnet and clear the variable. While displaying the contents read from one of the above mentioned source.

You should be used text file for logging application actions.

I would suggest to store the logs in a file instead of keeping everythingin a variable. I personaly always do that by using a logging function which creates an individual log file for each user each day. Like that you have a better control over your logs and dont have to worry about your preformance problem. Have a look at this example:
internal static void WriteLog(string str, string clientNumber)
{
StreamWriter logWriter = null;
string todayDateString = DateTime.Now.Day.ToString() + "-" + DateTime.Now.Month.ToString() + "-" + DateTime.Now.Year.ToString();
string fullLogFileName = todayDateString + "_" + clientNumber + "_log.txt";
string LogPath = #"\\server\folder\Logs\";
string fullLogFilePathWithName = LogPath + fullLogFileName;
if (!File.Exists(fullLogFilePathWithName))
{
logWriter = new StreamWriter(fullLogFilePathWithName, true);
logWriter.WriteLine(DateTime.Now.ToString("d.MM.yyyy h:mm") + " - " + str);
logWriter.Flush();
}
else
{
logWriter = File.AppendText(fullLogFilePathWithName);
logWriter.WriteLine(DateTime.Now.ToString("d.MM.yyyy h:mm") + " - " + str);
logWriter.Flush();
}
logWriter.Dispose();
logWriter.Close();
}

.net already has built in support for tracing / logging:
http://msdn.microsoft.com/en-us/library/zs6s4h68.aspx
However, we use log4net, and I'm quite happy with it:
http://logging.apache.org/log4net/
From your question it is not quite clear if the log is displayed by the server or the client. However, log4net has support for logging over the net, e.g. an UPD Appender.

Directory.Move(): Access to Path is Denied

I'm writing this Windows Form Application in Visual Studio 2010 using C#.
There is a Execute button on the form, the user will hit the button, the program will generate some files and are stored in the Output folder (which is created by the program using Directory.CreateDirectory())
I want to create an Archive folder to save the output files from previous runs.
In the beginning of each run, I try to move the existing Output folder to the Archive folder, then create a new Output folder. Below is the function I ran to move directory.
static void moveToArchive()
{
if (!Directory.Exists("Archive")) Directory.CreateDirectory("Archive");
string timestamp = DateTime.Now.ToString("yyyyMMddHHmms");
try
{
Directory.Move("Output", "Archive\\" + timestamp);
}
catch(Exception e)
{
Console.WriteLine("Can not move folder: " + e.Message);
}
}
The problem I ran into confuses me a lot...
There are some times that I can successfully move the Output folder to archive, but sometimes it fails.
The error message I got from catching the exception is Access to path 'Output' is denied.
I have checked that all the files in the Output folder are not in use. I don't understand how access is denied sometimes and not all the times.
Can someone explain to me and show me how to resolve the problem?
--Edit--
After HansPassant comment, I modified the function a little to get the current directory and use the full path. However, I'm still having the same issue.
The function now looks like this:
static void moveToArchive()
{
string currentDir = Environment.CurrentDirectory;
Console.WriteLine("Current Directory = " + currentDir);
if (!Directory.Exists(currentDir + "\\Archive")) Directory.CreateDirectory(currentDir + "\\Archive");
string timestamp = DateTime.Now.ToString("yyyyMMddHHmms");
try
{
Directory.Move(currentDir + "\\Output", currentDir + "\\Archive\\" + timestamp);
}
catch(Exception e)
{
Console.WriteLine("Can not move folder: " + e.Message);
}
}
I printed out the current directory and it is just as what I was expecting, and I'm still having trouble using full path. Access to path 'C:\Users\Me\Desktop\FormApp\Output' is denied.
--Edit--
Thank you everyone for answering and commenting.
I think some of you miss this part so I'm going stress it a bit more.
The Directory.Move() sometimes work and sometimes fails.
When the function succeed, there was no problem. Output folder is moved to Archive
When the function fails, the exception message I got was Access to path denied.

Thank you all for the replies and help. I have figured out what the issue was.
It is because there was a file that's not completely closed.
I was checking the files that were generated, and missed the files the program was reading from.
All files that were generated were closed completely. It was one file I used StreamReader to open but didn't close. I modified the code and am now not having problem, so I figure that's were the issue was.
Thanks for all the comments and answers, that definitely help me with thinking and figuring out the problem.

See http://windowsxp.mvps.org/processlock.htm
Sometimes, you try to move or delete a file or folder and receive access violation or file in use - errors. To successfully delete a file, you will need to identify the process which has locked the file. You need to exit the process first and then delete the particular file. To know which process has locked a file, you may use one of the methods discussed in this article.
Using Process Explorer - download from http://download.sysinternals.com/files/ProcessExplorer.zip
Process Explorer shows you information about which handles and DLLs processes have opened or loaded.
Download Process Explorer from Microsoft site and run the program.
Click the Find menu, and choose Find Handle or DLL...
Type the file name (name of the file which is locked by some process.)
After typing the search phrase, click the Search button
You should see the list of applications which are accessing the file.

I bumped on the same problem recently. Using PE I'd figured that only process using that particular directory was explorer.exe. I'd opened few windows with explorer, one pointing to parent directory of one that I was about to move.
It appeared, that after I visited that sub-folder and then returned (even to root level!) the handle was still being kept by explorer, so C# was not able to modify it in any way (changing flags, attributes etc.).
I had to kill that explorer window in order to made C# operate properly.

File.SetAttributes(Application.dataPath + "/script", FileAttributes.Normal);
Directory.Move(Application.dataPath + "/script", Application.dataPath + "/../script");
This fixed my problem.

Try this:
If this does not solve, maybe check/change the antivirus, or the some other program is locking some file in or the folder.
static object moveLocker = new object();
static void moveToArchive()
{
lock (moveLocker)
{
System.Threading.Thread.Sleep(2000); // Give sometime to ensure all file are closed.
//Environment.CurrentDirectory = System.AppDomain.CurrentDomain.BaseDirectory;
string applicationPath = System.AppDomain.CurrentDomain.BaseDirectory;
string archiveBaseDirectoryPath = System.IO.Path.Combine(applicationPath, "Archive");
if (!Directory.Exists(archiveBaseDirectoryPath)) Directory.CreateDirectory(archiveBaseDirectoryPath);
String timestamp = DateTime.Now.ToString("yyyyMMddHHmms");
String outputDirectory = System.IO.Path.Combine(Environment.CurrentDirectory, "Output");
String destinationTS = System.IO.Path.Combine(archiveBaseDirectoryPath, timestamp);
try
{
Directory.Move(outputDirectory, destinationTS);
}
catch (Exception ex)
{
Console.WriteLine("Can not move folder " + outputDirectory + " to: " + destinationTS + "\n" + ex.Message);
}
}
}

I had the same problem, it failed sometimes but not all the time. I thought I'd wrap it in a Try Catch block and present the user with an Access Denied message and once I wrapped it in the Try Catch block it stopped failing. I can't explain why.
If existingFile.FileName <> newFileName Then
Dim dir As New IO.DirectoryInfo(existingFile.FilePath)
Dim path As String = System.IO.Path.GetDirectoryName(dir.FullName)
newFileName = path & "\" & newFileName
File.SetAttributes(existingFile.FilePath, FileAttributes.Normal)
Try
IO.File.Move(existingFile.FilePath, newFileName)
Catch ex As Exception
End Try
End If

I had a similar problem. Renamed many directories in a loop when following the certain template. From time to time the program crashed on different directories. It helped to add a sleep thread before Directory.Move. I need to create some delay.
But it slows down the copying process.
foreach (var currentFullDirPath in Directory.GetDirectories(startTargetFullDirectory, "*", SearchOption.AllDirectories))
{
var shortCurrentFolderName = new DirectoryInfo(currentFullDirPath).Name.ToLower();
if (shortCurrentFolderName.Contains(shortSourceDirectoryName))
{
// Add Thread.Sleep(1000);
Thread.Sleep(1000);
var newFullDirName = ...;
Directory.Move(currentFullDirPath, newFullDirName);
}
}

Program update code issue

Hey everyone.
I've developed a simple code to auto-update my program. The way it works is:
Program downloads a remote file that has the version string in it. If the version string is bigger than the program's, auto update initiates.
The program downloads the newest version of the program using a remote link with DownloadAsync.
The program creates a new batch file that kills the current app (The program itself), deletes the current program, and renames the new one to the application's name. Then, it runs the new updated application and deletes itself.
However, I'm facing an issue when the batch file is actually executed. Here is my code:
private void WC_Completed(object sender, AsyncCompletedEventArgs e)
{
StringBuilder Batch = new StringBuilder();
Batch.AppendLine("#echo off");
Batch.AppendLine("taskkill /IM " + Process.GetCurrentProcess().ProcessName + ".exe /F");
Batch.AppendLine("ping localhost > nul");
Batch.AppendLine("del /f " + (char)34 + Application.ExecutablePath + (char)34);
Batch.AppendLine("ren " + (char)34 + Application.StartupPath + #"\update.exe" + (char)34 + " " + Process.GetCurrentProcess().ProcessName + ".exe");
Batch.AppendLine((char)34 + Application.ExecutablePath + (char)34);
Batch.AppendLine("del %0");
File.WriteAllText(Application.StartupPath + #"\update.bat", Batch.ToString(), Encoding.Default);
Process.Start(Application.StartupPath + #"\update.bat");
}
For some reason, it doen't kill the current application, or it just takes too much, and the whole process is going crazy. It just runs the unupdated app because the renaming doesn't work, which causes a loop.
Can you please point out my error? I'm trying to see what's wrong!
Thank you!

There's an easier way to update a program if it consists of one executable file:
Rename a running executable using File.Move to something like my.exe.bak.
Put an updated executable in the place of the old one.
Launch the new copy using Process.Start("my.exe") and exit the old one.
Upon launch test if my.exe.bak exists and try to delete it. You won't succeed first time, but the backup will be deleted eventually.
This way you won't need any .bat trickery.
You can also enchance this algorithm by passing PID (Process ID) of the old instance to the new one through command line arguments and then using Process.GetProcessById(pid).WaitForExit(); to be able to delete my.exe.bak on the first launch and handle update process completion.

FileSystemWatcher and Monitoring Config File Changes

I have about 5-6 Server Manager programs that write their own configuration file out to a particualr folder, such as C:\ACME. The config files all end with a *ServerConfig.cfg" where * = Program name that created it.
I have a Windows service that has a FileSystemWatcher setup that I want to FTP the configuration files each time the program updates. I've gotten everything to work, but I'm noticing that the different Server Manager programs are behaving differently.
When saving a configuration file, the FileSystemWatcher is picking up two "change" events. This is causing my program to FTP the configuration file twice where I only need it once.
In other instances I'm seeing where it may create 4, 5, or 6 "change" events when saving a configuration file.
What is the best way to handle processing/FTPing these files when they are really done saving only one time.
I really dont want o set something up to poll the directory for filechanges every so often... and like the idea that each time a configuration is saved, I get a duplicate copy along with a date/timestamp appended to the filename copied elsewhere.
I have seen lots of suggestions Googling around and even here on Stackoverflow, but nothing that seems to be all-in-one for me.
I suppose I could put the filename in a queue when a "change" event occurred if it didn't already exist in the queue. Not sure if this is the best approx.
Here is my sample code:
Startup-code:
private DateTime _lastTimeFileWatcherEventRaised = DateTime.Now;
_watcherCFGFiles = new FileSystemWatcher();
_watcherCFGFiles.Path = #"C:\ACME";
_watcherCFGFiles.IncludeSubdirectories = true;
_watcherCFGFiles.Filter = "*ServerConfig.cfg";
_watcherCFGFiles.NotifyFilter = NotifyFilters.Size;
//_watcherCFGFiles.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.FileName;
_watcherCFGFiles.Changed += new FileSystemEventHandler(LogFileSystemChanges);
_watcherCFGFiles.Created += new FileSystemEventHandler(LogFileSystemChanges);
_watcherCFGFiles.Deleted += new FileSystemEventHandler(LogFileSystemChanges);
_watcherCFGFiles.Renamed += new RenamedEventHandler(LogFileSystemRenaming);
_watcherCFGFiles.Error += new ErrorEventHandler(LogBufferError);
_watcherCFGFiles.EnableRaisingEvents = true;
Here is that actual handler for the "change" event. I'm skipping the first "change" event if the second is within 700ms. But this doesn't account for the files that make 3-4 change events...
void LogFileSystemChanges(object sender, FileSystemEventArgs e)
{
string log = string.Format("{0} | {1}", e.FullPath, e.ChangeType);
if( e.ChangeType == WatcherChangeTypes.Changed )
{
if(DateTime.Now.Subtract(_lastTimeFileWatcherEventRaised).TotalMilliseconds < 700)
{
return;
}
_lastTimeFileWatcherEventRaised = DateTime.Now;
LogEvent(log);
// Process file
FTPConfigFileUpdate(e.FullPath);
}
}

I had the exact same issue. I used a HashMap that mapped filenames to times of writes, I then used this as a lookup table for files to check and see if the changed event had been applied very quickly. I defined some epsilon (for me it was about 2 seconds to make sure events were flushed). If the time found in the map was older than that I would put it on a queue to be processed. Essentially all I had to do was keep the HashMap up to date with events and changes and this worked out (although you may want to change your epsilon value depending on your application).

Its normal this behavior because the antivirus system or other programs make more writes when a file change the content. I usually create a (global) HashTable and check if the filename exists, if don't, put the filename in it and start and an asynchronous operation to remove the filename after 3-5 seconds.

This is expected behavior - so you need to figure out how to handle it in your particular case.
The file system does not have a concept of "program done working with this file". I.e. one can write editor that updates (open/write/close) file on every keystroke. File system will report a lot of updates, but from the user point of view there is only one update when the editor is closed.