How to write log file in c

Question

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

User · Answer

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

User · Answer

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

User · Answer

Use File AppendAllText instead   File AppendAllText filePath    log txt   log

User · Answer

This is add new string in the file  using  var file   new StreamWriter filePath    log txt   true                         file WriteLine log               file Close

User · Answer

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

User · Answer

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

User · Answer

if  File Exists filename     No File  Create       fs   File Create filename       fs Close      if File ReadAllBytes   Length  gt   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

User · Answer

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

User · Answer

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

User · Answer

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

[c#] How to write log file in c#?

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