How do I Log the Class file without the path in log4net - configuration

Question

I want to be able to log the class file and line number in my log file so I am using the following config...
<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<!--etc-->
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level (%file:%line) %logger => %message%newline" />
</layout>
</appender>
However the %file attribute is making my log file entries waaaay too long to read comfortably....
2009-08-07 16:41:55,271 [7] INFO (O:\mystream\aevpallsrv\DotNet\com.mycompany.au\myapp\Myappp\Controller.cs:75) MyApp.Controller => Controller.EnqueueWorkerThreads() - START
Is there a way to show just the class file ('Controller.cs') instead of the full path to the file also???
Michael

Answer 1

Although you're asking about the file name, I believe you can use %type to get the fully qualified type name (a.b.className). If you just want the class name, use %type{1}
Note that any method that generates caller information (%file and %type) have a performance cost associated with them.
As an aside, you can bypass the performance hit by naming the Logger using the Type name.
namespace MyNamespace
{
public class Foo
{
private static ILog log = LogManager.GetLogger(typeof(Foo));
}
}
Your conversion pattern would look like:
"%date [%thread] %-5level %logger %message"
Where your logger would be "MyNameSpace.Foo". Likewise, if you only want the class name, use "%logger{1}, which will resolve as "Foo".
One of the best advantages to this approach is that you can leverage log4net's hierarchical repository system to adjust logging levels per type:
<!-- all classes in MyNamespace are warn -->
<logger name="MyNamespace">
<level value="WARN" />
</logger>
<!-- only Foo is in debug -->
<logger name="MyNamespace.Foo">
<level value="DEBUG" />
</logger>

Answer 2

Out of the box, PatternLayout supports only the %file token. What you can do is subclass PatternLayout and add your own pattern, say %filename, and for this token only output the name of the file.