Parse the command on the given line.
        
        :param line: The raw input line
        :type line: str

def precmd(self, line):
        """Parse the command on the given line.
        
        :param line: The raw input line
        :type line: str
        
        """
        line = line.lower()
        
        if line == 'exit' or line == 'help':
            return line
        
        try:
            parts = stmt.parseString(line)

            if len(parts) == 2:
                self.simple_report(parts)
            else:
                self.grouped_report(parts)
        except ParseException, err:
            pass
        
        return "none"