How to specify common application data folder for log4net

environment-variableslog4netlogging

I want log4net to write log files (using RollingFileAppender) to a subfolder of the common application data folder (e.g. C:\Documents and Settings\All Users\Application Data\Company\Product\Logs).
However, on Win XP, there is no environment variable that specifies this folder. We have %ALLUSERSPROFILE%, we have %APPDATA%, but there is nothing like %ALLUSERSAPPDATA%.
Programatically, I could use Environment.SpecialFolder.CommonApplicationData, but I need to put it in the log4net config, something like this:

<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
   <file value="%ALLUSERSAPPDATA%\Company\Product\Logs\error.log" />
</appender>

OK, we could define this in our setup, but maybe someone comes up with a better idea?

Best Solution

We just use this:

<param name="File" value="${ALLUSERSPROFILE}/Company/Product/Logs/error.log"/>

It works great.

This line can simply be inserted into your current appender configuration:

<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
   <param name="File" value="${ALLUSERSPROFILE}/Company/Product/Logs/error.log"/>
</appender>

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C# – Have log4net use application config file for configuration data

Add a line to your app.config in the configSections element

<configSections>
 <section name="log4net" 
   type="log4net.Config.Log4NetConfigurationSectionHandler, log4net, Version=1.2.10.0, 
         Culture=neutral, PublicKeyToken=1b44e1d426115821" />
</configSections>

Then later add the log4Net section, but delegate to the actual log4Net config file elsewhere...

<log4net configSource="Config\Log4Net.config" />

In your application code, when you create the log, write

private static ILog GetLog(string logName)
{
    ILog log = LogManager.GetLogger(logName);
    return log;
}

.net – How to track down log4net problems

First you have to set this value on the application configuration file:

<configuration>
   <appSettings>
      <add key="log4net.Internal.Debug" value="true"/>
   </appSettings>
</configuration>

Then, to determine the file in which you want to save the output you can add the following code in the same .config file:

<configuration>
...

<system.diagnostics>
    <trace autoflush="true">
        <listeners>
            <add 
                name="textWriterTraceListener" 
                type="System.Diagnostics.TextWriterTraceListener" 
                initializeData="C:\tmp\log4net.txt" />
        </listeners>
    </trace>
</system.diagnostics>

...
</configuration>

You can find a more detailed explanation under 'How do I enable log4net internal debugging?' in the log4net FAQ page.

Best Solution

Related Solutions

C# – Have log4net use application config file for configuration data

.net – How to track down log4net problems

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