Can you use DIR to list files in subfolders ?

815 vues (au cours des 30 derniers jours)
John le 12 Mar 2012
Commenté : Jorge Leon le 5 Déc 2022
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

Réponse acceptée

Walter Roberson
Walter Roberson le 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'));
Now subdirinfo{K} is the structure of information about the .mat files in the directory dirinfo(K).name
  6 commentaires
Vids deo
Vids deo le 9 Août 2016
Hi Walter,
I'm kinda understanding what you're saying. But please clarify if the statement means the following in words - "Assign NULL to the elements of the 'dirinfo' structure array which have '0' or FALSE in the isdir field." --Vidya
Walter Roberson
Walter Roberson le 10 Août 2016
Only if you understand that assigning NULL means to delete them.

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Plus de réponses (6)

Jan le 3 Mai 2017
In modern Matlab versions:
files = dir('D:\Data\**\*.mat')
  13 commentaires
Yiting Zhu
Yiting Zhu le 13 Nov 2022
This solution really works!
Jorge Leon
Jorge Leon le 5 Déc 2022
Useful and simple. Thanks!

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Walter Roberson
Walter Roberson le 13 Mar 2012
filetofind = 'data.mat';
dirinfo = dir();
dirinfo(~[dirinfo.isdir]) = []; %remove non-directories
tf = ismember( {}, {'.', '..'});
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;
[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 );
  15 commentaires
Walter Roberson
Walter Roberson le 22 Mai 2012
Modifié(e) : Walter Roberson le 19 Juil 2019
You can combine the load() into a single statement:
thisdata = load( fullfile(thisdirname,filetofind), vartofind, vartofind1 );
xlswrite( thisoutname, thisdata.(vartofind) );
xlswrite( thisoutname, thisdata.(vartofind1) );
However, you need to either write to different file names or else use range specifications on the xlswrite() -- otherwise the data from the second xlswrite() will overwrite the first.
John le 22 Mai 2012
Thanks very much for your help. I got it working.

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Frederic Moisy
Frederic Moisy le 12 Mar 2012
  1 commentaire
John le 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

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Luke Melo
Luke Melo le 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'));
  4 commentaires
Walter Roberson
Walter Roberson le 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.
lena kappa
lena kappa le 1 Déc 2022
@Walter Roberson is there a way to save all those files in a new folder?

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Matthias le 3 Mai 2017
Modifié(e) : Matthias le 3 Mai 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.
[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 commentaires
Guillaume le 19 Juil 2019
What files? What new folder?
It doesn't look like your question has much to do with the question being answered here, so please start your own question. Give as many details as possible about what you're trying to do.

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Ba Mo
Ba Mo le 21 Avr 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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