Develop Reference

IOException: The process cannot access the file 'file path' because it is being used by another process in Console Application in C#

I am running Console_Application-A in which I am calling another Console_Application-B (in which I am creating log file for Error/Exception).
But when I am running Console_Application-B individually its working properly but when I am running Console_Application-A at that time I am getting an Exception when Application need to write an Error in log file.(Error.txt).
IOException: The process cannot access the file 'Error.txt' because it
is being used by another process
please guide me in this issue.
Code for Writing Error log
public static bool IsFileLocked(FileInfo file)
{
FileStream stream = null;
try
{
stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None);
}
catch (IOException)
{
return true;
}
finally
{
if (stream != null)
stream.Close();
}
return false;
}
catch (Exception e)
{
string filePath =Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location) + "\\Error.txt";
FileInfo FInfo = new FileInfo(filePath);
var FileState = IsFileLocked(FInfo);
while (FileState){
FileState = IsFileLocked(FInfo);
}
if (!FileState){
using (StreamWriter writer = new StreamWriter(filePath, true))
{
writer.WriteLine("Message :" + e.Message + "<br/>" + Environment.NewLine + "StackTrace :" + e.StackTrace +"" + Environment.NewLine + "Date :" + DateTime.Now.ToString());
writer.WriteLine(Environment.NewLine + "-----------------------------------------------------------------------------" + Environment.NewLine);
writer.Dispose();
}
}
}

There is no need first to check if the file is locked and then access it, as between the check and the access some other process may still get a lock on the file.
using System;
using System.IO;
class DirAppend
{
public static void Main()
{
using (StreamWriter w = File.AppendText("log.txt"))
{
Log("Test1", w);
Log("Test2", w);
}
using (StreamReader r = File.OpenText("log.txt"))
{
DumpLog(r);
}
}
public static void Log(string logMessage, TextWriter w)
{
w.Write("\r\nLog Entry : ");
w.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),
DateTime.Now.ToLongDateString());
w.WriteLine(" :");
w.WriteLine(" :{0}", logMessage);
w.WriteLine ("-------------------------------");
}
public static void DumpLog(StreamReader r)
{
string line;
while ((line = r.ReadLine()) != null)
{
Console.WriteLine(line);
}
}
}
Source - https://msdn.microsoft.com/en-us/library/3zc0w663(v=vs.110).aspx

Compress file - Sharing violation on path

I currentlywork on an android application, and I have to develop a function to compress files into directory.
To get all the files, I use the DirectoryInfo() and FileInfo() class and then the ZipArchive() and ZipArchiveEntry() class to create my .zip file.
The problem I have is when I open the file to compress with a FileStream to copy data into my ZipArchive entry. I got a sharing violation on path error when I use the OpenRead() function.
I already check the permissions in my Manifest and try several methods like ZipFile.CreateFromDirectory but I still have the same problem.
Thank you by advance for your help.
Here is my code :
public void Compress(DirectoryInfo directory)
{
string identifiantSC = currentSceneSelected.Id_Scene;
string typeSceneSelected = currentSceneSelected.type_Scene;
if (!Directory.Exists (Path.Combine (pathProject, "Archive"))) {
Directory.CreateDirectory (Path.Combine (pathProject, "Archive"));
}
string pathSceneDir = Path.Combine (pathProject, typeSceneSelected + "_" + identifiantSC);
string pathZipDir = Path.Combine (pathProject, "Archive");
foreach (var fileToCompress in directory.GetFiles ()) {
if (!File.Exists (Path.Combine (pathZipDir, typeSceneSelected + "_" + identifiantSC + ".zip"))) {
try {
var fileZip = new FileStream (Path.Combine (pathZipDir, typeSceneSelected + "_" + identifiantSC + ".zip"), FileMode.Create);
archive = new ZipArchive (fileZip, ZipArchiveMode.Create);
ZipArchiveEntry readmeEntry = archive.CreateEntry (fileToCompress.Name, CompressionLevel.Optimal);
FileStream originalFileStream = fileToCompress.OpenRead();
originalFileStream.CopyTo (readmeEntry.Open ());
} catch (FileLoadException e){
Console.WriteLine ("FILE LOAD EXCEPTION : " + e);
} catch (AccessViolationException e){
Console.WriteLine ("ACCESS VIOLATION EXCEPTION : " + e);
} catch (UnauthorizedAccessException e){
Console.WriteLine ("ACCESS EXCEPTION : " + e);
}
}
else {
using (var fileZip = new FileStream (Path.Combine (pathZipDir, typeSceneSelected + "_" + identifiantSC + ".zip"), FileMode.Open)) {
using (archive = new ZipArchive (fileZip, ZipArchiveMode.Update)) {
ZipArchiveEntry readmeEntry = archive.CreateEntry (fileToCompress.Name, CompressionLevel.Optimal);
FileStream originalFileStream = fileToCompress.OpenRead ();
originalFileStream.CopyTo (readmeEntry.Open ());
originalFileStream.Close ();
}
}
}
}
}

How to write log file in c#?

How would I write a log file in c#?
Currently i have a timer with this statement which ticks every 20 secs:
File.WriteAllText(filePath+"log.txt", log);
For everything that i want logged i do this:
log += "stringToBeLogged";
As you can assume the string log just grows and grows as the program runs. (I don't even know if there is a maximum chars per string?)
I assume that there must be better ways of doing this. i just thought that it would be heavy to write the whole file again and again for every time something is added to the log.

From the performance point of view your solution is not optimal. Every time you add another log entry with +=, the whole string is copied to another place in memory. I would recommend using StringBuilder instead:
StringBuilder sb = new StringBuilder();
...
sb.Append("log something");
...
// flush every 20 seconds as you do it
File.AppendAllText(filePath+"log.txt", sb.ToString());
sb.Clear();
By the way your timer event is probably executed on another thread. So you may want to use a mutex when accessing your sb object.
Another thing to consider is what happens to the log entries that were added within the last 20 seconds of the execution. You probably want to flush your string to the file right before the app exits.

create a class create a object globally and call this
using System.IO;
using System.Reflection;
public class LogWriter
{
private string m_exePath = string.Empty;
public LogWriter(string logMessage)
{
LogWrite(logMessage);
}
public void LogWrite(string logMessage)
{
m_exePath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
try
{
using (StreamWriter w = File.AppendText(m_exePath + "\\" + "log.txt"))
{
Log(logMessage, w);
}
}
catch (Exception ex)
{
}
}
public void Log(string logMessage, TextWriter txtWriter)
{
try
{
txtWriter.Write("\r\nLog Entry : ");
txtWriter.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),
DateTime.Now.ToLongDateString());
txtWriter.WriteLine(" :");
txtWriter.WriteLine(" :{0}", logMessage);
txtWriter.WriteLine("-------------------------------");
}
catch (Exception ex)
{
}
}
}

Use File.AppendAllText instead:
File.AppendAllText(filePath + "log.txt", log);

public static void WriteLog(string strLog)
{
StreamWriter log;
FileStream fileStream = null;
DirectoryInfo logDirInfo = null;
FileInfo logFileInfo;
string logFilePath = "C:\\Logs\\";
logFilePath = logFilePath + "Log-" + System.DateTime.Today.ToString("MM-dd-yyyy") + "." + "txt";
logFileInfo = new FileInfo(logFilePath);
logDirInfo = new DirectoryInfo(logFileInfo.DirectoryName);
if (!logDirInfo.Exists) logDirInfo.Create();
if (!logFileInfo.Exists)
{
fileStream = logFileInfo.Create();
}
else
{
fileStream = new FileStream(logFilePath, FileMode.Append);
}
log = new StreamWriter(fileStream);
log.WriteLine(strLog);
log.Close();
}
Refer Link:
blogspot.in

as posted by #randymohan, with using statements instead
public static void WriteLog(string strLog)
{
string logFilePath = #"C:\Logs\Log-" + System.DateTime.Today.ToString("MM-dd-yyyy") + "." + "txt";
FileInfo logFileInfo = new FileInfo(logFilePath);
DirectoryInfo logDirInfo = new DirectoryInfo(logFileInfo.DirectoryName);
if (!logDirInfo.Exists) logDirInfo.Create();
using (FileStream fileStream = new FileStream(logFilePath, FileMode.Append))
{
using (StreamWriter log = new StreamWriter(fileStream))
{
log.WriteLine(strLog);
}
}
}

Very convenient tool for logging is http://logging.apache.org/log4net/
You can also make something of themselves less (more) powerful. You can use http://msdn.microsoft.com/ru-ru/library/system.io.filestream (v = vs.110). Aspx

Add log to file with Static Class
public static class LogWriter
{
private static string m_exePath = string.Empty;
public static void LogWrite(string logMessage)
{
m_exePath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
if (!File.Exists(m_exePath + "\\" + "log.txt"))
File.Create(m_exePath + "\\" + "log.txt");
try
{
using (StreamWriter w = File.AppendText(m_exePath + "\\" + "log.txt"))
AppendLog(logMessage, w);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
private static void AppendLog(string logMessage, TextWriter txtWriter)
{
try
{
txtWriter.Write("\r\nLog Entry : ");
txtWriter.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),DateTime.Now.ToLongDateString());
txtWriter.WriteLine(" :");
txtWriter.WriteLine(" :{0}", logMessage);
txtWriter.WriteLine("-------------------------------");
}
catch (Exception ex)
{
}
}
}

if(!File.Exists(filename)) //No File? Create
{
fs = File.Create(filename);
fs.Close();
}
if(File.ReadAllBytes().Length >= 100*1024*1024) // (100mB) File to big? Create new
{
string filenamebase = "myLogFile"; //Insert the base form of the log file, the same as the 1st filename without .log at the end
if(filename.contains("-")) //Check if older log contained -x
{
int lognumber = Int32.Parse(filename.substring(filename.lastIndexOf("-")+1, filename.Length-4); //Get old number, Can cause exception if the last digits aren't numbers
lognumber++; //Increment lognumber by 1
filename = filenamebase + "-" + lognumber + ".log"; //Override filename
}
else
{
filename = filenamebase + "-1.log"; //Override filename
}
fs = File.Create(filename);
fs.Close();
}
Refer link:
http://www.codeproject.com/Questions/163337/How-to-write-in-log-Files-in-C

This is add new string in the file
using (var file = new StreamWriter(filePath + "log.txt", true))
{
file.WriteLine(log);
file.Close();
}

There are 2 easy ways
StreamWriter - http://www.dotnetperls.com/streamwriter
Log4Net like Log4j(Java) - http://www.codeproject.com/Articles/140911/log4net-Tutorial

If your application is multithreaded then in some environments file.appendalltext could give error like file already in use and if you skip that then you could lose important logs .
For that you can use
Lock object technique with file.append.. in that case it will wait for existing process to close and the write your log
This can also save you from adding other libraries in your source

Above code will throw: Process can't access the file because it is being used by another process error because of File.Create(m_exePath + "\" + "log.txt"); if you will comment out this it will work as expected
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
namespace SolutionLogWriter
{
public static class LogWriterClass
{
private static string m_exePath = string.Empty;
public static void LogWrite(string logMessage)
{
m_exePath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
string fullpath = m_exePath + "\\" + "log.txt";
if (File.Exists(fullpath))
{
File.Delete(fullpath);
}
// File.Create(fullpath);
try
{
FileStream fs = new FileStream(fullpath, FileMode.OpenOrCreate);
using (StreamWriter w = new StreamWriter(fs))
AppendLog(logMessage, w);
}
catch (Exception ex)
{
AppendLog(ex.ToString());
}
}
private static void AppendLog(string logMessage, TextWriter txtWriter=null)
{
try
{
txtWriter.Write("\r\nLog Entry : ");
txtWriter.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(), DateTime.Now.ToLongDateString());
txtWriter.WriteLine(" :");
txtWriter.WriteLine(" :{0}", logMessage);
txtWriter.WriteLine("-------------------------------");
}
catch (Exception ex)
{
txtWriter.Write(ex.Message);
}
}
}
}

Disposing File Object Properly

Ok so heres the thing. When ever a trigger is hit i append my logs in a specific folder. The code works fine and it appends it correctly but if i try to manually delete the folder from the desktop its giving a "The action cannot be completed cause the folder/file is open in another program";
i guess im not disposing it right but i dont know where i missed it. I know its the folder that is attached to the process cause i tried to delete the .log file inside and it allowed me.
private void LogEvent(string filename,bool AppendTxt,string msg)
{
string sLogFormat = DateTime.Now.ToShortDateString().ToString() + " " + DateTime.Now.ToLongTimeString().ToString() + " ==> ";
msg = sLogFormat + msg;
// create directory
if (System.IO.Directory.Exists("C:\\Users\\DT-Npax\\Desktop\\LOGS1") != true)
{
Directory.CreateDirectory("C:\\Users\\DT-Npax\\Desktop\\LOGS1");
}
string dailyLog = "C:\\Users\\DT-Npax\\Desktop\\LOGS1" + "\\" + filename + ".log";
FileStream FS = null;
//write or append txt
if (!AppendTxt)
{
if (File.Exists(dailyLog))
{
File.Delete(dailyLog);
}
using (FS = File.Create(dailyLog)) { }
FS.Close();
StreamWriter TXT_WRITE = new StreamWriter(dailyLog);
TXT_WRITE.WriteLine(msg);
TXT_WRITE.Close();
}
else
{
if (!File.Exists(dailyLog))
{
using (FS = File.Create(dailyLog)) { }
FS.Close();
}
FileStream FSAppend = new FileStream(dailyLog, FileMode.Append, FileAccess.Write);
StreamWriter TXT_WRITE = new StreamWriter(FSAppend);
TXT_WRITE.WriteLine(msg);
TXT_WRITE.Close();
FSAppend.Close();
}
}

Your code does seem to close the file properly but not in an exception-safe manner.
You also have some unnecessary code in there (like using (FS = File.Create(dailyLog)) { } FS.Close(); ).
The smallest modification looks like this:
else
{
//if (!File.Exists(dailyLog))
//{
// using (FS = File.Create(dailyLog)) { }
// FS.Close();
//}
using (FileStream FSAppend = new FileStream(dailyLog, FileMode.Append, FileAccess.Write))
using (StreamWriter TXT_WRITE = new StreamWriter(FSAppend))
{
TXT_WRITE.WriteLine(msg);
}
//TXT_WRITE.Close();
//FSAppend.Close();
}
But I would rewrite this whole method like:
private void LogEvent(string filename,bool AppendTxt,string msg)
{
string sLogFormat = DateTime.Now.ToShortDateString().ToString() + " "
+ DateTime.Now.ToLongTimeString().ToString() + " ==> ";
msg = sLogFormat + msg;
// create directory
if (System.IO.Directory.Exists("C:\\Users\\DT-Npax\\Desktop\\LOGS1") != true)
{
Directory.CreateDirectory("C:\\Users\\DT-Npax\\Desktop\\LOGS1");
}
string dailyLog = "C:\\Users\\DT-Npax\\Desktop\\LOGS1" + "\\" + filename + ".log";
if (AppendText)
System.IO.File.AppendAllText(dailylog, msg);
else
System.IO.File.WriteAllText(dailylog, msg);
}
There is no need to pre-create or delete files.

Wrap the streams in a using block since they implement IDisposable.
I must say this code is a little odd...
using (FS = File.Create(dailyLog)) { }
FS.Close();
StreamWriter TXT_WRITE = new StreamWriter(dailyLog);
TXT_WRITE.WriteLine(msg);
TXT_WRITE.Close();
Shouldn't it be something like:
using (FileStream FS = File.Create(dailyLog))
{
using(StreamWriter TXT_WRITE = new StreamWriter(dailyLog))
{
TXT_WRITE.WriteLine(msg);
}
}

Open existing file, append a single line

I want to open a text file, append a single line to it, then close it.

You can use File.AppendAllText for that:
File.AppendAllText(#"c:\path\file.txt", "text content" + Environment.NewLine);

using (StreamWriter w = File.AppendText("myFile.txt"))
{
w.WriteLine("hello");
}

Choice one! But the first is very simple. The last maybe util for file manipulation:
//Method 1 (I like this)
File.AppendAllLines(
"FileAppendAllLines.txt",
new string[] { "line1", "line2", "line3" });
//Method 2
File.AppendAllText(
"FileAppendAllText.txt",
"line1" + Environment.NewLine +
"line2" + Environment.NewLine +
"line3" + Environment.NewLine);
//Method 3
using (StreamWriter stream = File.AppendText("FileAppendText.txt"))
{
stream.WriteLine("line1");
stream.WriteLine("line2");
stream.WriteLine("line3");
}
//Method 4
using (StreamWriter stream = new StreamWriter("StreamWriter.txt", true))
{
stream.WriteLine("line1");
stream.WriteLine("line2");
stream.WriteLine("line3");
}
//Method 5
using (StreamWriter stream = new FileInfo("FileInfo.txt").AppendText())
{
stream.WriteLine("line1");
stream.WriteLine("line2");
stream.WriteLine("line3");
}

Or you could use File.AppendAllLines(string, IEnumerable<string>)
File.AppendAllLines(#"C:\Path\file.txt", new[] { "my text content" });

Might want to check out the TextWriter class.
//Open File
TextWriter tw = new StreamWriter("file.txt");
//Write to file
tw.WriteLine("test info");
//Close File
tw.Close();

The technically best way is probably this here:
private static async Task AppendLineToFileAsync([NotNull] string path, string line)
{
if (string.IsNullOrWhiteSpace(path))
throw new ArgumentOutOfRangeException(nameof(path), path, "Was null or whitepsace.");
if (!File.Exists(path))
throw new FileNotFoundException("File not found.", nameof(path));
using (var file = File.Open(path, FileMode.Append, FileAccess.Write))
using (var writer = new StreamWriter(file))
{
await writer.WriteLineAsync(line);
await writer.FlushAsync();
}
}

File.AppendText will do it:
using (StreamWriter w = File.AppendText("textFile.txt"))
{
w.WriteLine ("-------HURRAY----------");
w.Flush();
}

//display sample reg form in notepad.txt
using (StreamWriter stream = new FileInfo("D:\\tt.txt").AppendText())//ur file location//.AppendText())
{
stream.WriteLine("Name :" + textBox1.Text);//display textbox data in notepad
stream.WriteLine("DOB : " + dateTimePicker1.Text);//display datepicker data in notepad
stream.WriteLine("DEP:" + comboBox1.SelectedItem.ToString());
stream.WriteLine("EXM :" + listBox1.SelectedItem.ToString());
}

We can use
public StreamWriter(string path, bool append);
while opening the file
string path="C:\\MyFolder\\Notes.txt"
StreamWriter writer = new StreamWriter(path, true);
First parameter is a string to hold a full file path
Second parameter is Append Mode, that in this case is made true
Writing to the file can be done with:
writer.Write(string)
or
writer.WriteLine(string)
Sample Code
private void WriteAndAppend()
{
string Path = Application.StartupPath + "\\notes.txt";
FileInfo fi = new FileInfo(Path);
StreamWriter SW;
StreamReader SR;
if (fi.Exists)
{
SR = new StreamReader(Path);
string Line = "";
while (!SR.EndOfStream) // Till the last line
{
Line = SR.ReadLine();
}
SR.Close();
int x = 0;
if (Line.Trim().Length <= 0)
{
x = 0;
}
else
{
x = Convert.ToInt32(Line.Substring(0, Line.IndexOf('.')));
}
x++;
SW = new StreamWriter(Path, true);
SW.WriteLine("-----"+string.Format("{0:dd-MMM-yyyy hh:mm:ss tt}", DateTime.Now));
SW.WriteLine(x.ToString() + "." + textBox1.Text);
}
else
{
SW = new StreamWriter(Path);
SW.WriteLine("-----" + string.Format("{0:dd-MMM-yyyy hh:mm:ss tt}", DateTime.Now));
SW.WriteLine("1." + textBox1.Text);
}
SW.Flush();
SW.Close();
}