force log4net to overwrite file

Question

I develop an application which does something each time in several runs.

I got much logging information in each run. So when a run was successfull (no exceptions thrown), and the users starts a new run, I want to overwrite the log file on starting the new run.

How can I achieve that?

Furthermore: How do I get the log-file name out of the Logger interface? I don't want to parse the App.xaml.cs

stuartd · Answer 1 · 2014-07-02T23:43:45.547

2

To overwrite the log file, use a FileAppender and set appendToFile to false:

appender name="FileAppender" type="log4net.Appender.FileAppender">
    <file value="log.txt" />
    <appendToFile value="false" />
    <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] .. etc ..  />
    </layout>
</appender>

However this will not be able to know if your run was successful, and will overwrite the file each time the app is run.

edited Jul 02 '14 at 23:43

answered Jul 02 '14 at 23:34

stuartd

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I already have this configuration. The question was, how can I force log4net to overwrite this file at runtime. Not only when the app starts. – Rico-E Jul 04 '14 at 18:07

score 0 · Accepted Answer · edited May 23 '17 at 10:27

The solution is:

public static void StartNewLogFile()
{
    Hierarchy hierachy = (Hierarchy)log4net.LogManager.GetRepository();
    Logger logger = hierachy.Root;

    var rootAppender = logger.Appenders.OfType<FileAppender>().FirstOrDefault();
    string filename = rootAppender != null ? rootAppender.File : string.Empty;

    while (logger != null)
    {
        foreach (IAppender appender in logger.Appenders)
        {
            FileAppender fileAppender = appender as FileAppender;
            if (fileAppender != null)
            {
                fileAppender.File = filename + "a";
                fileAppender.File = filename;
                fileAppender.ActivateOptions();
            }
        }
        logger = logger.Parent;
    }

    File.Delete(filename + "a");
}

With a big help from: Programatically force a new log file with Log4Net

force log4net to overwrite file

2 Answers2