Is there any way to list all folders ONLY in the level directly below a selected directory?

I want to generate a list of all of the subfolders within a directory. I was using genpath for this. Unfortunately, each of these subfolders also has 4 subfolders of tehir own, and I don't want them included in this list.

Is there any command that can list the folders only one level below the directory I indicate?

[Stephen23]

Note that answers and comments which use the indexing 3:end, e.g.

{subFolders(3:end).name} % Start at 3 to skip . and ..

and

subDirsNames = {subDirs(3:end).name};

are fundamentally fragile and should be avoided as general solutions. This has been discussed many times:

https://www.mathworks.com/matlabcentral/answers/13978-list-of-files-sorting#answer_19278

https://www.mathworks.com/matlabcentral/answers/40949-omitting-pointers-when-listing-folder-contents#answer_50568

https://www.mathworks.com/matlabcentral/answers/166629-is-there-any-way-to-list-all-folders-only-in-the-level-directly-below-a-selected-directory#comment_510206

https://www.mathworks.com/matlabcentral/answers/484430-using-struct-dir-selpath-what-do-and-mean-as-struct-name#answer_395754

https://www.mathworks.com/matlabcentral/answers/1699230-folder-listing-with-dir-on-mac#answer_945260

As Walter Roberson wrote: "That code is wrong on every operating system that MATLAB has ever run on".

The recommended approach is to specify a non-empty DIR search name, or use e.g. ISMEMBER, SETDIFF, or similar:

https://www.mathworks.com/matlabcentral/answers/166629-is-there-any-way-to-list-all-folders-only-in-the-level-directly-below-a-selected-directory#comment_624696

Answer 1

[Image Analyst]

John, simply use dir():

topLevelFolder = pwd; % or whatever, such as 'C:\Users\John\Documents\MATLAB\work'
% Get a list of all files and folders in this folder.
files = dir(topLevelFolder);
% Get a logical vector that tells which is a directory.
dirFlags = [files.isdir];
% Extract only those that are directories.
subFolders = files(dirFlags); % A structure with extra info.
% Get only the folder names into a cell array.
subFolderNames = {subFolders(3:end).name} % Start at 3 to skip . and ..

% Optional fun : Print folder names to command window.
for k = 1 : length(subFolderNames)
	fprintf('Sub folder #%d = %s\n', k, subFolderNames{k});
end

[Fatima Mansour]

Is it possible to select a folder and open all the subfolders and files, under the chosen path, in a tree recursively rather than listing them?

[Image Analyst]

Sure, you can use imageDataStore(), or dir. See attached example for dir()

[Fatima Mansour]

Thank you! I actually want to open a folder selected from the hard drive and display its subfolders and files in a tree GUI. If I want to choose the folder(using uigetdir for example), how do I then open this folder as a parent or root node in a tree? I don't want them to be listed in the command window.

[Image Analyst]

Sorry, I don't have any graphical way to show the folders in a tree diagram.

The code will still work though, to process the files inside in whatever way you want, such as to display the images or open/extract the spreadsheets, etc.

[Fatima Mansour]

Thank you anyway!

[lena kappa]

@Image Analyst i tried your code and got the names of all the jpg images in all the subfolders in my folder but i can't copy or move those images in another folder(which is what i want to do).

Is there a way to do that with your code?

Take all the jpg images in all the subfolders and move them in the same folder?

[Image Analyst]

If you want to "move" them to the same folder, or make a copy of them in the same folder as where they currently are, you're going to have to give them a unique name. You can't have two files in the same folder with the same name.

[lena kappa]

Hi again @Image Analyst I dont want to copy the subfolders but the files inside the subfoldes.

What i mean is that i have a folder with lets say 3 subfolders that each such subfolder has 10 jpg images. I want to take all those images and move or copy them in an other folder alltogether.

[Image Analyst]

Did you try to modify the file I attached. It's just a simple one to use ** to included subfolders. Here is the code:

% Demo by Image Analyst
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format short g;
format compact;
fontSize = 22;
markerSize = 20;
% Copies all the files from one folder to another folder.
clc;    % Clear the command window.
workspace;  % Make sure the workspace panel is showing.
format compact;
% Define input and output folders.
% CHANGE THESE FOLDER NAMES!!!!!!
topLevelFolder = pwd;
outputFolder = uigetdir(pwd);
if strcmp(outputFolder, topLevelFolder)
    errorMessage = sprintf('Error: the output folder must be different than the input folder');
    uiwait(warndlg(errorMessage));
    return;
end
% Check to see that both folders exist.
if ~isfolder(topLevelFolder)
    errorMessage = sprintf('Error: The following input folder does not exist:\n%s', topLevelFolder);
    uiwait(warndlg(errorMessage));
    return;
end
if ~isfolder(outputFolder)
    errorMessage = sprintf('Error: The following output folder does not exist:\n%s', outputFolder);
    uiwait(warndlg(errorMessage));
    return;
end
% Get a list of files to copy in inputFolder and all subfolders.
filePattern = fullfile(topLevelFolder, '**/*.*'); % All files.
% filePattern = fullfile(topLevelFolder, '**/*.m'); % m-files.
fileNamesToTransfer = dir(filePattern);
numFiles = length(fileNamesToTransfer);
% Do the copying.
for k = 1 : numFiles
    % Get the base file name.
    baseFileName = fileNamesToTransfer(k).name;
    inputFolder = fileNamesToTransfer(k).folder;
    % Create the full input and output filenames.
    fullInputFileName = fullfile(inputFolder, baseFileName);
    fullOutputFileName = fullfile(outputFolder, baseFileName);
    fprintf(1, 'Now copying file #%d of %d: %s to %s\n', ...
        k, numFiles, fullInputFileName, fullOutputFileName);
    copyfile(fullInputFileName, fullOutputFileName);
end
uiwait(msgbox('Done copying files!', 'modal'));

[lena kappa]

@Image Analyst THank you so much!

Answer 2

[John]

Thanks, this is great.

I ran into another problem. It seems to list two directories I don't want, '.' and '..", whcih apparently correspond to the folders containing these subfolders.

Is there any way to make it so that it removes those entries? I want to make this script as intuitive as possible so that it needs minimal modification later on.

[Sean de Wolski]

Those are always the first two (current directory ., up one directory ..) , just remove them.

d = dir;
d(1:2) = []

[Soo Min Kang]

It's actually not always guaranteed that . and .. will appear as the first two elements, especially if the folder contains files/directories that begin with underscores (_). To be on the safe side, use logical & operands when obtaining the logical vector that identifies directories:

dirFlags = [files.isdir] & ~strcmp({files.name},'.') & ~strcmp({files.name},'..')

[Walter Roberson]

Soo Min Kang is correct: all of the characters !"#$%&'()*+,- and space sort before '.' does, so even if there were a guarantee of sorting, the first two entries might not be '.' and '..' . Also, on MS Windows NTFS file systems, the sort order is not defined by Microsoft.

I more typically write something like

dinfo = dir();
dinfo(ismember( {dinfo.name}, {'.', '..'})) = [];  %remove . and ..

[Ian Hunter]

thanks walter, this is a nice solution which worked for me

[Kristoffer Walker]

Soo Min, thanks.

Answer 3

[Paulo Abelha]

 function [subDirsNames] = GetSubDirsFirstLevelOnly(parentDir)
    % Get a list of all files and folders in this folder.
    files = dir(parentDir);
    % Get a logical vector that tells which is a directory.
    dirFlags = [files.isdir];
    % Extract only those that are directories.
    subDirs = files(dirFlags);
    subDirsNames = cell(1, numel(subDirs) - 2);
    for i=3:numel(subDirs)
        subDirsNames{i-2} = subDirs(i).name;
    end
end

[Jan]

@Paulo: As mentioned some years ago already, skipping the first two folders is not reliable, because '.' and '..' are not guaranteed to be listed on top. Easier, secure and without a loop:

   function [subDirsNames] = GetSubDirsFirstLevelOnly(parentDir)
   % Get a list of all files and folders in this folder.
   files    = dir(parentDir);
   names    = {files.name};
   % Get a logical vector that tells which is a directory.
   dirFlags = [files.isdir] & ...
              ~strcmp(names, '.') && ~strcmp(names, '..');
   % Extract only those that are directories.
   subDirsNames = names(dirFlags);
   end

[Bart Ribbens]

one & too much, so the correct version is:

function [subDirsNames] = GetSubDirsFirstLevelOnly(parentDir)
% Get a list of all files and folders in this folder.
files    = dir(parentDir);
names    = {files.name};
% Get a logical vector that tells which is a directory.
dirFlags = [files.isdir] & ~strcmp(names, '.') & ~strcmp(names, '..');
% Extract only those that are directories.
subDirsNames = names(dirFlags);
end

[SM]

Thanks for this excellent format!

Questions

For my problem,

subDirsNames =

1×2 cell array

{'Instance01'} {'Instance02'}

and each folder ( Instance01 and Instance02) contains list of .dat files. First I want to access all the .dat files in {'Instance01'} and perform some operations. once it is done, I want to access data from {'Instance02'}.

How can I do that? Thanks in advance!

[Image Analyst]

SM I will show you two ways:

% Method 1 -- use dir()
fileList = dir('**/*.dat')
for k = 1 : length(fileList)
	thisFileName = fullfile(fileList(k).folder, fileList(k).name);
	fprintf('Processing file %d of %d : %s\n', k, length(fileList), thisFileName);
end
% Method 2 -- use a fileDatastore
fds = fileDatastore(pwd, 'FileExtensions','.dat', 'ReadFcn', @readmatrix)
for k = 1 : length(fds.Files)
	thisFileName = fds.Files{k};
	fprintf('Processing file %d of %d : %s\n', k, length(fds.Files), thisFileName);
end

[Benjamin Azrieli]

Jan and Bart Ribbens solutions worked perfectly for me - thanks Soo Min Kang for starting them off

[Svetlana Piner]

Thanks to Paulo for a nice little function easy to drop in the code. Super nicely done :)

[Image Analyst]

Here is a vectorized version (no for loop):

function [subDirsNames] = GetSubDirsFirstLevelOnly(parentDir)
    % Get a list of all files and folders in this folder.
    files = dir(parentDir);
    % Get a logical vector that tells which is a directory.
    dirFlags = [files.isdir];
    % Extract only those that are directories.
    subDirs = files(dirFlags); % A structure with extra info.
    % Get only the folder names into a cell array.
    subDirsNames = {subDirs(3:end).name};
end