an> <span class="more" data-toggle="popover" data-placement="bottom" data-content="the second csv to be joined">stations.csv</span>
                        <span class="more" data-toggle="popover" data-placement="bottom" data-content="this redirects output to a file instead of stdout (the console)">></span> finished/<span class="more" data-toggle="popover" data-placement="bottom" data-content="notdir is a function - given a filepath, it returns only the file name, without the directory path">$(notdir $@)</s