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Natural-Order Filename Sort

version 3.3.0 (22.9 KB) by Stephen Cobeldick
Alphanumeric sort of filenames or filepaths, with customizable numeric format.

16.9K Downloads

Updated 14 Jul 2021

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Editor's Note: This file was selected as MATLAB Central Pick of the Week

To sort the elements of a string/cell array use NATSORT:
To sort the rows of a string/cell array use NATSORTROWS:
### 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 ###
>> B = {'test2.m'; 'test10-old.m'; 'test.m'; 'test10.m'; 'test1.m'};
>> sort(B) % Wrong number order:
ans =
'test.m'
'test1.m'
'test10-old.m'
'test10.m'
'test2.m'
>> natsortfiles(B) % Shorter names before longer:
ans =
'test.m'
'test1.m'
'test2.m'
'test10.m'
'test10-old.m'
%% Directory Names:
>> C = {'A2-old\test.m';'A10\test.m';'A2\test.m';'A1\test.m';'A1-archive.zip'};
>> sort(C) % Wrong number order, and '-' sorts before '\':
ans =
'A1-archive.zip'
'A10\test.m'
'A1\test.m'
'A2-old\test.m'
'A2\test.m'
>> natsortfiles(C) % Shorter names before longer:
ans =
'A1\test.m'
'A1-archive.zip'
'A2\test.m'
'A2-old\test.m'
'A10\test.m'
>> D = {'A1\B', 'A+/B', 'A/B1', 'A=/B', 'A\B0'};
>> sort(D)
ans = 'A+/B' 'A/B1' 'A1\B' 'A=/B' 'A\B0'
>> natsortfiles(D)
ans = 'A\B0' 'A/B1' 'A1\B' 'A+/B' 'A=/B'
>> F = {'test_new.m'; 'test-old.m'; 'test.m'};
>> sort(F) % Note '-' sorts before '.':
ans =
'test-old.m'
'test.m'
'test_new.m'
>> natsortfiles(F) % Shorter names before longer:
ans =
'test.m'
'test-old.m'
'test_new.m'

Cite As

Stephen Cobeldick (2021). Natural-Order Filename Sort (https://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort), MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2010b
Compatible with any release
Platform Compatibility
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