Include header only once at the top of a rolling file

Question

Is it possible to only include header information at the top of a rolling file? I have the following config file: ```

``` When I run my application, for example twice I get header information twice e.g. ``` [Header] The Log line [Header] The Log line etc ``` I am looking to achieve the following: ``` [Header] The Log line The Log line etc ```

Accepted Answer

The easiest way I've found to do this is to create a class that inherits from RollingFileAppender and overwrites like this the WriteHeader method :

```
using System.IO;
using System.Text;
using log4net.Core;
using log4net.Layout;
using log4net.Util;
using log4net.Appender;

namespace CsvLogging
{
    public class HeaderOnceAppender : RollingFileAppender 
    {
        protected override void WriteHeader()
        {
            try
            {
                if (LockingModel.AcquireLock().Length == 0)
                {
                    base.WriteHeader();
                }
            }
            finally
            {
                LockingModel.ReleaseLock();
            }
        }
    }
}
```

then use this class as appender :

```
<appender name="CsvFileAppender" type="CsvLogging.HeaderOnceAppender">
```

Include header only once at the top of a rolling file

Solution

Problem