Natural-Order Filename Sort

Alphanumeric sort of filenames or filepaths, with customizable numeric format.

To sort the elements of a string/cell array use NATSORT:

http://www.mathworks.com/matlabcentral/fileexchange/34464-customizable-natural-order-sort

To sort the rows of a string/cell array use NATSORTROWS:

http://www.mathworks.com/matlabcentral/fileexchange/47433-natural-order-row-sort

### Summary ###

Alphanumeric sort the text in a string/cell/structure array. Sorts the strings taking into account the values of any number substrings. Compare for example:

>> A = {'a2.txt', 'a10.txt', 'a1.txt'};

>> sort(A)

ans = 'a1.txt' 'a10.txt' 'a2.txt'

>> natsortfiles(A)

ans = 'a1.txt' 'a2.txt' 'a10.txt'

By default NATSORTFILES interprets all consecutive digits as integer numbers, the number substring recognition can be specified using a regular expression: see NATSORT for details.

NATSORTFILES does not perform a naive natural-order sort, but sorts the filenames and file extensions separately to ensure a dictionary sort, where shorter filenames always sort before longer ones. Likewise filepaths are split at each file-separator character, and each level of the file hierarchy is sorted separately.

### Example with DIR ###

P = 'C:\SomeDir\SubDir';

S = dir(fullfile(P,'*.txt'));

S = natsortfiles(S);

for k = 1:numel(S)

F = fullfile(P,S(k).name)

end

### File Dependency ###

The natural-order sort is provided by the function NATSORT (File Exchange 34464). All of NATSORT's optional inputs are supported by NATSORTFILES.

### Examples ###

>> A = {'a2.txt', 'a10.txt', 'a1.txt'}

>> sort(A)

ans = 'a1.txt' 'a10.txt' 'a2.txt'

>> natsortfiles(A)

ans = 'a1.txt' 'a2.txt' 'a10.txt'

>> B = {'test_new.m'; 'test-old.m'; 'test.m'};

>> sort(B) % Note '-' sorts before '.':

ans =

'test-old.m'

'test.m'

'test_new.m'

>> natsortfiles(B) % Shorter names before longer:

ans =

'test.m'

'test-old.m'

'test_new.m'

>> C = {'test2.m'; 'test10-old.m'; 'test.m'; 'test10.m'; 'test1.m'};

>> sort(C) % Wrong number order:

ans =

'test.m'

'test1.m'

'test10-old.m'

'test10.m'

'test2.m'

>> natsortfiles(C) % Shorter names before longer:

ans =

'test.m'

'test1.m'

'test2.m'

'test10.m'

'test10-old.m'

%% Directory Names:

>> D = {'A2-old\test.m';'A10\test.m';'A2\test.m';'A1archive.zip';'A1\test.m'};

>> sort(D) % Wrong number order, and '-' sorts before '\':

ans =

'A10\test.m'

'A1\test.m'

'A1archive.zip'

'A2-old\test.m'

'A2\test.m'

>> natsortfiles(D) % Shorter names before longer:

ans =

'A1archive.zip'

'A1\test.m'

'A2\test.m'

'A2-old\test.m'

'A10\test.m'