How to recursively go through all directories and sub directories and process files?

So I have a single directory with sub directories and sub directories and then files (its a mess). I want to go to each folder at end ( I dont care about directories) and process the files in it (be it .txt .jpg etc). I kinda got a way to list all folders using the dirwalk function from here, - https://www.mathworks.com/matlabcentral/fileexchange/32036-dirwalk-walk-the-directory-tree , but I don't know two things. How to figure out if a path (the function outputs all possible paths, thats what i understood) is not directory with sub directories, but a directory with images or text files, so I can process them. After choosing a path, I need to figure out how to loop through files. Or is there an easier way I'm missing? any advice would be appreciated!

Example of direc structure:

Main Directory>

>> Dir 1

>> fold1

>>txt files

>>fold2

>>files

>>Dir 2

...etc

Answer 1

[Guillaume]

Since R2016b, dir can recurse through subdirectories using **. So it's as simple as:

rootdir = 'C:\somewhere\somedirectory';
filelist = dir(fullfile(rootdir, '**\*.*'));  %get list of files and folders in any subfolder
filelist = filelist(~[filelist.isdir]);  %remove folders from list

[KAE]

So glad to know dir is recursive! Another example if it helps anyone: if you want to search recursively for all files named, for example, readData*.m, you could do it as follows,

rootdir = 'C:\somewhere\somedirectory';
filelist = dir(fullfile(rootdir, '**\readData*.m')); 
% Returns readDataCsv.m, readDataXml.m, readDataTxt.m, etc

[Daniel Poiesz]

I just learned the leading '**\' is required for recursion and '*.mat' would only find files in the root directory.

[Darcy Cordell]

Wow, this is truly incredible and saved me so much time.

[Michael]

For me I had to swap '**\*.*' for '**/*.nii' since on linux I got

Error using dir

Characters adjacent to a ** wildcard must be file separators.

[Steven Lord]

For me I had to swap '**\*.*' for '**/*.nii' since on linux

You could adapt Guillaume's fullfile usage. Since the MATLAB sessions used by MATLAB Answers to evaluate code run on Linux, it will automatically use the appropriate filesep to assemble the directory path.

rootdir = 'ThisIsMyRootDirectory';
filesep

ans = '/'

directoryName = fullfile(rootdir, '**', '*.*') 

directoryName = 'ThisIsMyRootDirectory/**/*.*'