Importing multiple text files from multiple folders

I wrote the following code to read the files I need.

runs = 33137;
folders = 22;
format = '%f%C%C';

filestop = folders;
for N = 1:filestop
    for n = 1:runs
        foldstr = num2str(N);
        indstr = num2str(n);

          filename = strcat('C:\PERALS_Ra-226\b',foldstr,'\Sample226Ra(',indstr,').txt');
          T = readtable(filename,'Delimiter',',','Format',format,'ReadVariableNames',false);
          col = n;
          A(:,col) = table2array(T(:,1:1));

          fileID = fopen(filename);
          tline = fgetl(fileID);
          grabd = textscan(tline,'%*f%*s%{M/d/yyyy h:mm:ss a}D','delimiter',',');
          stopdate(1,col) = datetime(grabd{1,1});
          for M = 1:15
              tline = fgetl(fileID);
          end
          grab = textscan(tline,'%*f%*s%d','delimiter',',');
          rt(1,col) = grab{1,1};

          for O = 1:15
              tline = fgetl(fileID);
          end
          grab = textscan(tline,'%*f%*s%f','delimiter',',');
          dt(1,col) = grab{1,1};

          fclose(fileID); 

      end
  end

The problem with my code is that there are a total of 33137 text files, however each folder does not have that many files. How can I change this code to read all of the files I need?

Answer 1

[Kai Domhardt]

What you want to do is check each folder individually for the number files in it.

folders = 22;
format = '%f%C%C';
filestop = folders;
for N = 1:filestop
  foldername = strcat('C:\PERALS_Ra-226\b',foldstr);
  listing = dir(foldername );
    for n = 3:length(listing)
        filename = [listing(n).folder filesep listing(n).name];
        if ~listing(n).isdir && ~isempty(strfind(filename, 'Sample226Ra'))
           ...

The for-loop starts at 3 in order to skip the parent folder '..' and the current folder '.'.

[Madison Lowe]

Thank you so much!!