Rename a lot of files

I have a lot of files with names 'Sample_1.csv, Sample_2.csv, Sample_3.csv, ..., Sample_101'. I would like to rename all of them to the format of Sample_xxx.csv, so it becomes like this: 'Sample_001.csv, Sample_002.csv, Sample_003.csv, ..., Sample_101'.

Can anyone help me? Thank you very much.

Answer 1

[Walter Roberson]

@Akira Agata's solution is perfectly usable. But here is a different approach that never converts to numeric and back

dinfo = dif('*.csv');
filenames = {dinfo.name};
new_filenames = regexprep(filenames, {'_(\d)\.', '_(\d\d)\.'}, {'_00$1.', '_0$1.'});
mask = ~strcmp(filenames, new_filenames);
cellfun(@(OLD, NEW) movefile(OLD,NEW), filenames(mask), new_filenames(mask));

The mask part is to avoid trying to movefile() a file to the same name. A file might have the same name after regexprep() if it did not follow the pattern at all, or if it already had 3 or more digits after the '_'

[Cheuk Yin Wong]

Thank you very much. What is the use of '~' in front of strcmp?

[Walter Roberson]

~ is logical negation. The strcmp() is looking for file names that are the same after text replacement; you do not want to process those (besides being inefficient, the movefile() woud complain about moving a file to itself.)

[Cheuk Yin Wong]

Thank you! It works very well.

Answer 2

[Akira Agata]

How about the following?

fileList = dir('*.csv');

for kk = 1:numel(fileList)
  fileNum = extractBetween(fileList(kk).name,'_','.csv');
  fileNum = str2double(fileNum);
  newFileName = sprintf("Sample_%03d.csv", fileNum);
  movefile(fileList(kk).name, newFileName);
end

[Cheuk Yin Wong]

Thank you!