title: Logback.xml configuration
body: <p>I am trying to configure the stout to save into a file.
   However, it is not saved to a file - do you have an idea why?.
   also - I want the log file name would be configurable inside the logback.xml
   something like {LOG_FILE_NAME} which will come from the cmd - is it possible? </p>
  
  <p>This is my logback.xml:</p>
  
  <pre><code> &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  
  &lt;!-- For assistance related to logback-translator or configuration  --&gt;
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  &lt;!--                                                                --&gt;
  &lt;configuration&gt;
    &lt;appender name="defaultLog" class="ch.qos.logback.core.rolling.RollingFileAppender"&gt;
      &lt;!--See also http://logback.qos.ch/manual/appenders.html#RollingFileAppender--&gt;
      &lt;File&gt;sarit_test.log&lt;/File&gt;
      &lt;encoder&gt;
        &lt;pattern&gt;%d{dd MMM yyyy HH:mm:ss.SSS} [%t] %-5p %x %F:%L - %m&lt;/pattern&gt;
      &lt;/encoder&gt;
      &lt;rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy"/&gt;
      &lt;triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy"&gt;
        &lt;MaxFileSize&gt;50000KB&lt;/MaxFileSize&gt;
      &lt;/triggeringPolicy&gt;
    &lt;/appender&gt;
    &lt;root level="INFO"&gt;
      &lt;appender-ref ref="defaultLog"/&gt;
    &lt;/root&gt;
  &lt;/configuration&gt;
  </code></pre>