Create an array of file names produced by system('dir /S *.ext')

Hi there,

I know that you can search directories and sub-directories to provide a list of file names that meet a particular criteria using the code below:

[status,list]=system('dir /S *.mp3');

My question is: is it possible to create an array from the file names generated this way in order to create a loop for further processing??

Thanks in advance...

Answer 1

[Richard Alcock]

You can use textscan to split the multiple lines of output from the system command into a cell array.

[status, list] = system( 'dir /B /S *.mp3' );
result = textscan( list, '%s', 'delimiter', '\n' );
fileList = result{1}

Note that I've added /B to the dir command to make the output easier to parse.

[bugguts99]

Thanks - works a treat!

[franco otaola]

is there any possibility of extract the name without the extension? thanks

Answer 2

[Sven Mesecke]

What's wrong with the MATLAB function 'dir'? You can add wildcards like .mp3 and get a struct array in return, whose name field can easily be converted into a cell array of filenames:

a=dir('S/*.ext');
b={a.name}

Otherwise there's a nice tool on MATLAB Central that uses regular expressions for dir: http://www.mathworks.com/matlabcentral/fileexchange/16216-regexpdir

[Mujhaid]

I want to ask how i can access each individual element of structure array?

[franco otaola]

is there any possibility of extract the name without the extension? thanks

[Walter Roberson]

Use fileparts() to extract the name without the extension.

[nvmnghia]

Why can't we use

b = [a.name]

here?

[Seung-Goo Kim]

@nvmnghia you can try it yourself on your computer. But now MATLAB supports something like Jupyter notebook on a virtual environment:

pwd

ans = '/users/mss.system.TC8Vlw'

unix('echo"" > thisfile1.txt'); unix('echo"" > ThatFile-1234.txt');
a = dir('*.txt')

a = 2×1 struct array with fields:
    name
    folder
    date
    bytes
    isdir
    datenum

b = [a.name]

b = 'ThatFile-1234.txtthisfile1.txt'

This will create a very wide character array by horizontally concatenating cated character arrays (i.e., file names). Then it becomes another problem to access each file. You usually can't do vertical concatenation because often the file names have different number of characters.

b = cat(1,a.name)

Error using cat
Dimensions of arrays being concatenated are not consistent.

So, this is why you want to cast them into a cell array, instead of a character array, as @Sven Mesecke wrote above.