Hello, I have a cell array with the list of files I would like to delete. However I would not like to use a for loop to loop through each file to delete it.

Files - A cell array of size 1x3 with file names to be deleted.

Files =

1×3 cell array

{'1.txt'} {'2.txt'} {'3.txt'}

Working Code :

for i = 1:length(Files)

delete(string(Files(i)));

end

However, I would like to write a single line of code without for loop to achieve the same.

Note: Every run of my code can have different number of files to be deleted. So hardcoding with the command

delete 1.txt 2.txt 3.txt

will not be helpful.

Answer 1

[Voss]

Pass the file names as arguments to delete(). Since the names are already in a cell array, this is easy:

delete(Files{:})

Demonstration:

% make some .txt files:
writematrix(1,'1.txt')
writematrix(2,'2.txt')
writematrix(3,'3.txt')

% get info about the .txt files:
fn = dir('*.txt') % 3 files found

fn = 3x1 struct array with fields:
    name
    folder
    date
    bytes
    isdir
    datenum

% construct a cell array with the file names:
Files = fullfile({fn.folder},{fn.name});

% delete the files:
delete(Files{:})

% confirm that all three files have been deleted:
fn = dir('*.txt') % 0 files found

fn = 

  0x1 empty struct array with fields:

    name
    folder
    date
    bytes
    isdir
    datenum

[Krishna Ghanakota]

Works great ! Thanks.

[Voss]

You're welcome!

[Steve Van Hooser]

@MathWorks Support Team: This use of calling delete with a cell array of file names is not documented but probably should be in the documentation for delete.

[Stephen23]

"This use of calling delete with a cell array of file names is not documented but probably should be in the documentation for delete."

This answer does not call DELETE with a cell array of filenames. In fact it calls DELETE with every filename as a separate input, exactly as documented: https://www.mathworks.com/help/matlab/ref/delete.html

This answer uses a comma-separated list generated from a cell array. A comma-separated list is a general syntactical feature of MATLAB that can be used with any function or operator:

https://www.mathworks.com/help/matlab/matlab_prog/comma-separated-lists.html

https://www.mathworks.com/matlabcentral/discussions/tips/847976-tutorial-comma-separated-lists-and-how-to-use-them

[Steve Van Hooser]

Yes, this is correct. Sorry for my error. DELETE does NOT take cell arrays as an input. (I just realized and was coming back to correct myself! You beat me to it.)

Thanks

Steve

Answer 2

[Chuguang Pan]

maybe you can use cellfun.

Files={'1.txt','2.txt','3.txt'};
cellfun(@delete,Files)

[Krishna Ghanakota]

I guess this is the same as the for loop. The documentation says

"cellfun(func,C) applies the function func to the contents of each cell of cell array C, one cell at a time."

I am looking at a time critical application and cannot afford looping of any sort.

Thank you.

[DGM]

I doubt that a small loop is going to be meaningfully slow compared to actually making changes to files.

Why not construct a command string and pass that to the system?

% this will probably break if filenames have spaces or other issues
files = {'1.txt','2.txt','3.txt'};
comstr = sprintf(repmat('%s ',[1 numel(files)]),files{:});
system(['rm ' comstr]);

I mean it sure doesn't sound like a great idea, but if that's the road we're on ...

[Walter Roberson]

You need to account for special characters in file names.

% this will probably break if filenames have spaces or other issues
files = {'1.txt','2.txt','3.txt'};
comstr = sprintf(repmat('"%s" ',[1 numel(files)]),files{:});
system(['rm ' comstr]);

[Krishna Ghanakota]

I get the following response

'rm' is not recognized as an internal or external command,

operable program or batch file.

[Image Analyst]

I think rm is a unix command. If you're on Windows, use del.