I have an administration console I'm building, and I want to display the logs created in Logback for my application. However, where those logs are stored is different per environment. I have several property files that define where the logs are stored:

<configuration>
  <property resource='log.properties'/>
  <property resource='log.${ENV:-prod}.properties'/>

  <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>${log.dir}/sync.log</file>
  ...
</configuration>

I'd like to find the value of ${log.dir} from Logback's Java API. I'd tried the following, but it doesn't have any of the properties defined in the resources. For example:

LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
 String logDir = loggerContext.getProperty("log.dir"); // this always returns null

So my question is what API calls should I be using?

Thanks
Charlie

If you'd rather have the stackoverflow karma I originally posted this there:
http://stackoverflow.com/questions/14271253/access-properties-defined-in-logback-programmatically