code: private static String getFromEnvFile(String varname)
  	{
  		if (osIsUnix())
  		{
  			//	Check if file exists at home
  			String	home = System.getenv("HOME");
  			String	varval = getFromEnvFile(varname, home+"/.tangorc");
  			if (varval!=null)
  				return varval;
  
  			//	Check default tangorc
  			String	tangorc = System.getProperty("TANGO_RC");
  			if (tangorc==null)
  				tangorc = "/etc/tangorc";
  			return getFromEnvFile(varname, tangorc);
  		}
  		else	//	WIN 32
  		{
  			
  			//	Check default tangorc
  			String	tangorc = System.getProperty("TANGO_RC");
  			if (tangorc==null)
  			{
  				String	tango_root = System.getenv("TANGO_ROOT");
  				if (tango_root==null)
  					return null;
  				tangorc = tango_root+"/tangorc";
  			}
  			return getFromEnvFile(varname, tangorc);
  		}
  	}
docs: ===================================================================