Matlab:renaming Files in a Sequential Order

Question

I have a number of text files with no Sequential Order :

010010.txt 010030.txt 010070.txt

How could I change the file names to:

text01.txt text02.txt ....

Is it possible not to re writte over the old directory but create a new directory

I have used the following script but the result is that it is working fine but it goes from text001.txt to text021.txt to then text041.txt

any idea?

directory  = 'C:\test\'; %//' Directory with txt files
filePattern = fullfile(directory, '*.txt'); %//' files pattern with absolute paths
old_filename = cellstr(ls(filePattern)) %// Get the filenames
file_ID = strrep(strrep(old_filename,'file',''),'.txt','') %// Get numbers associated with each file

file_ID_doublearr = str2double(file_ID)

file_ID_doublearr = file_ID_doublearr - min(file_ID_doublearr)+1

file_ID = strtrim(cellstr(num2str(file_ID_doublearr)))

str_zeros = arrayfun(@(t) repmat('0',1,t), 4-cellfun(@numel,file_ID),'uni',0) %// Get zeros string to be pre-appended to each filename

new_filename = strcat('file',str_zeros,file_ID,'.txt') %// Generate new filenames

cellfun(@(m1,m2) movefile(m1,m2),fullfile(directory,old_filename),fullfile(directory,new_filename)) %// Finally rename files with the absolute paths

Answer 1

That looks pretty complicated. I would simply make a system call to move all of the files to a new directory, then sequentially rename each file one at a time with additional system calls. It also looks like you're using Windows, so I'll provide a solution for that platform. You have the beginning right where you are reading in the files from a source directory.

directory  = 'C:\test\'; %// Directory with txt files
directoryToCopyOver = 'C:\out\'; %// Directory where you want to copy the files over

%// Copy source directory to target directory
system(['xcopy ' directory ' ' directoryToCopyOver]);

filePattern = fullfile(directoryToCopyOver, '*.txt'); %//' files pattern with absolute paths
names = dir(filePattern); %// Find all files with above pattern

%// For each file we have...
for idx = 1 : numel(names)
    name = names(idx).name; %// Get a name of a file
    %// Rename this file to textxx.txt
    outName = sprintf('text%2.2d.txt', idx);

    %// Call system and rename the file
    system(['ren ' directoryToCopyOver name ' ' directoryToCopyOver outName]);
end

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Some important things to note is that I use system to make system calls to your Windows command prompt. I use xcopy to copy a whole directory from one point to another. In this case, this would be your source directory over to a new target directory. After I do this, I invoke MATLAB's dir to determine all of the file names that match the particular pattern you have laid out, which is all of the text files.

Then, for each text file name we have, we read in this name, then create an output name of type textxx.txt, where xx is a number starting from 1 to as many text files as we have, and then I invoke the Windows command prompt command ren to rename the file from the original name to the new name. Also, take a look at sprintf from MATLAB. It is designed to create strings using formatting delimiters. If you see how I called it, %2.2d means that I am expecting the number to be two digits long, and should the number be less than two digits, fill the spaces with a zero. If you want to increase the amount of digits, simply add more to each place. For example, if you want to have 4 digits, do %4.4d, and so on. This will properly create the right string so that we can rename the right file in this new directory.

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Hope this helps!