-back function cb. If the call-back
                    returns false then the algorithm returns without considering
                    further matches in the current file, or any further files.
                  </p>
                  <p>
                    The parameter <span class="emphasis"><em>files</em></span> can include wild card
                    characters '*' and '?', if the parameter recurse is true then
                    searches sub-directories for matching file names.
                  