function [filename] = getfilename(ds, scnls, starttimes)
   %GETFILENAME returns a filename that is associated with a single SCNL
   %  filename= getfilename(ds, scnlobject, starttime)
   %    where:
   %    DS is the datasource object
   %    SCNLOBJECT is a scnlobject with station/channel/network/location
   %    information.
   %    STARTTIME is a matlab formatted time, or a string
   %
   % getfile is capable of traversing directory trees.
   %
   % [filename] = getfilename(ds, [],[],[]) will return a sample-string.
   % ex.
   %  >> ds = datasource('file','myfiles/%04d/%02d/thisfile%04d_%s%s.dat',...
   %      'year', 'month','day','station','channel');
   %  >> getfile(ds,[],[])
   %  ans =
   %     myfiles/[YEAR]/[MONTH]/thisfile[DAY]_[STATION][CHANNEL].dat
   %
   %  >> getfilename(ds,scnlobject('OKCF','EHZ'),'12/31/2008 04:03:21')
   %  ans =
   %     myfiles/2008/12/thisfile0031_OKCFEHZ.dat
   %
   %
   % see also SETFILENAME
   
   % AUTHOR: Celso Reyes, Geophysical Institute, Univ. of Alaska Fairbanks
   % $Date$
   % $Revision$
   
   % Day numbers at start of each month.  Used within to calculate "jday".
   monthadd = [ 0 31 59 90 120 151 181 212 243 273 304 334 ];
   
   if ~ds.usefile
      warning('Datasource:noAssociatedFiles','No files have been associated with this datasource');
      filename = [];
      return
   end
   
   %
   % if numel(scnl) > 1
   %   warning('Datasource:multipleSCNL',...
   %     'An array of SCNL was passed as the argument.  Only search for a single SCNL at a time');
   % end
   if isnumeric(starttimes) && ~isempty(starttimes)
      for n=1:numel(starttimes)
         st(n) = {starttimes(n)};
      end
      starttimes = st;
      clear st
   end
   if ~iscell(starttimes)
      starttimes = {starttimes};
   end
   filename = cell(numel(scnls),numel(starttimes));
   
   if isempty(filename) %show the generic file name
      %return a THEORETICAL filename
      year = '[YEAR]';
      jday ='[JDAY]';
      month ='[MONTH]';
      day ='[DAY]';
      hour ='[HOUR]';
      minute ='[MINUTE]';
      second ='[SECOND]';
      station = '[STATION]';
      channel = '[CHANNEL]';
      location = '[LOCATION]';
      network = '[NETWORK]';
      stringToShow = regexprep(ds.file_string,'(%|%0)(\d|)d','%s');
      % build the file arg string
      if isempty(ds.file_args)
         filename = {stringToShow};
      else
         z = cellfun(@eval,ds.file_args,'UniformOutput',false);
         filename = {sprintf(stringToShow,z{:})};
      end
   else %get detailed file.for n=1:numel(scnls)
      
      for n=1:numel(scnls)
         scnl = scnls(n);
         station = get(scnl,'station');
         channel = get(scnl,'channel');
         location = get(scnl,'location');
         network = get(scnl,'network');
         
         for m = 1:numel(starttimes)
            starttime = starttimes{m};
            
            
            %pull all the data that may be required to parse out files & directories
            
            % If we have a datenum, use the fast built-in version of datevec
            if isnumeric(starttime)
               [year, month, day, hour, minute, second] = datevecmx(starttime);
            else
               [year, month, day, hour, minute, second] = datevec(starttime);
            end
            
            second = round(second);
            
            % The following few IF statements handle possible rounding issues
            if second == 60
               second = 0; minute = minute+1;
            end
            if minute == 60
               minute = 0; hour = hour + 1;
            end
            if hour == 24
               hour = 0; day = day + 1;
            end
            
            % Calculate day number
            leapadd = +((mod(year,400) == 0) | ((mod(year,4) == 0) & (mod(year,100) ~= 0)) & (month > 2));
            jday = monthadd(month) + day + leapadd;
            
            stringToShow = ds.file_string;
            % build the file arg string
            if isempty(ds.file_args)
               filename = {stringToShow};
            else
               z = cellfun(@eval,ds.file_args,'UniformOutput',false);
               filename(n,m) = {sprintf(stringToShow,z{:})};
            end
         end
      end
      
   end
   filename = filename(:);
   %basic location of all archives
end