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Can you use DIR to list files in subfolders ?

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John
John on 12 Mar 2012
Commented: Jorge Castillo on 9 Jan 2020
Hello,
Would somebody be able to advise me on how to use DIR to find the dates that each file was last modified with a .mat extension in all sub folders in current directory?
This code does not look in sub directories. Also how to you specify the .mat extension.
files = dir(datenum)
Many thanks

Accepted Answer

Walter Roberson
Walter Roberson on 12 Mar 2012
You cannot do that in a single dir() call.
You need one dir() call on the current folder, and you look at the isdir() field of the results to see which names correspond to folders:
dirinfo = dir();
dirinfo(~[dirinfo.isdir]) = []; %remove non-directories
Then do a step to remove the folder names "." and ".." so you do not infinite loop.
Then you loop over all those names and look inside each of the designated folders:
subdirinfo = cell(length(dirinfo));
for K = 1 : length(dirinfo)
thisdir = dirinfo(K).name;
subdirinfo{K} = dir(fullfile(thisdir, '*.mat'));
end
Now subdirinfo{K} is the structure of information about the .mat files in the directory dirinfo(K).name
  6 Comments
Walter Roberson
Walter Roberson on 10 Aug 2016
Only if you understand that assigning NULL means to delete them.

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More Answers (6)

Jan
Jan on 3 May 2017
In modern Matlab versions:
files = dir('D:\Data\**\*.mat')
  9 Comments
Jorge Castillo
Jorge Castillo on 9 Jan 2020
For those using a previous version of R2016b, I propose to download the subdir function from here. Then create a script with the foll. lines and run it (F5):
a = mfilename('fullpath');
b = mfilename();
a = strrep(a,b,'');
addpath(a) % Adding the script current path
spath= 'D:\titi'; % Directory where the files are placed
list_struc = subdir(fullfile(spath, '*.c')); %Result : a List (as structure)...
% having the fullfile names of the desired file (eg. *.c)

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Walter Roberson
Walter Roberson on 13 Mar 2012
filetofind = 'data.mat';
dirinfo = dir();
dirinfo(~[dirinfo.isdir]) = []; %remove non-directories
tf = ismember( {dirinfo.name}, {'.', '..'});
dirinfo(tf) = []; %remove current and parent directory.
numsubdir = length(dirinfo);
lastmod = inf * ones(numsubdir,1);
for K = 1 : numsubdir
subdirinfo = dir(fullfile(dirinfo(K).name, filetofind));
if ~isempty(subdirinfo)
lastmod(K) = subdirinfo(1).datenum;
end
end
[sortedmod, sortorder] = sort(lastmod);
sordorder(~isfinite(sortedmod)) = []; %directories without data.mat
for K = 1 : length(sortorder)
thisdirnum = sortorder(K);
thisoutname = sprintf('file%d.xls', K);
%copy from the subdirectory in to a sequentially named .xls file
copy( fullfile( dirinfo(thisdirnum).name, filetofind ), thisoutname );
end
  15 Comments
John
John on 22 May 2012
Thanks very much for your help. I got it working.
Regards
John

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Frederic Moisy
Frederic Moisy on 12 Mar 2012
  1 Comment
John
John on 12 Mar 2012
Hello Frederic,
Would you mind helping me code this for my application. I've been trying for hours with no luck.
Thank you
John

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Luke Melo
Luke Melo on 25 Nov 2019
Found this article very useful. Here's the code I use to select a folder from a dialogue window and find all the files, png here for example, within all subdirectories:
path = uigetdir('/Users/user/')
files = dir(fullfile(path,'**','*.png'));
  3 Comments
Walter Roberson
Walter Roberson on 25 Nov 2019
The line I show with fullfile() is an extra step to extract fully qualified file names from the structure that is returned by dir() . When the '**' wildcard is used with dir() each different result might come from a different directory, and the same name might show up with respect to different directories, so it becomes important to put together the folder name and file name.

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Matthias
Matthias on 3 May 2017
Edited: Matthias on 3 May 2017
Although this does not answer the whole question it adresses the title (which is what I was looking for): to get a list of all(!) subfolders below a specified folder or drive one could use the dos command like this:
[s, r] = dos('dir X:\folder\ /s /b /A:D');
folders = regexpi(r, '\n', 'split')';
Using the /s option the dos dir command will go down all the way (no option to specifiy a max recursion depth here - beware of long execution times!), with attribute D (/A:D) only directories will be returned and finally the /b option gives us a nice plain list (as a very long string) that can be easily split for further use.
Edit:
[s, r] = dos('dir X:\folder\*.mat /s /b');
matFiles = regexpi(r, '\n', 'split')';
will obviously give you the list of all .mat files, the date of these can easily be obtained with another dir() call:
l = cellfun(@dir, matFiles);
changeTimes = [l.datenum]';
  4 Comments

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Ba Mo
Ba Mo on 21 Apr 2019
as lots of users reported above, new versions of matlab support the following command dir('**/*.mat');
However, old versions of matlab don't support this
instead of writing a large code, inspect the structure field "isfield" and so on, you could just easily ask DOS (or the command prompt) to do it for you. the output from MS-DOS isn't formatted, so you need to split the one block string to separate lines
newline = char(10); %char(10) is the character for line-break, or "enter"
[~,all_mats] = system('dir /s /b *.mat'); %you can also simply write: !dir /s /b *.mat
all_mats = strsplit(all_mats,newline)';
all_mats(cellfun(@isempty,all_mats))=[]; %the last entry/line might be an empty cell. delete it.

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