How to remove first few characters from multiple file names?

I have multiple files with similar first few characters stored in a folder. How would I remove the first few letters from multiple files so that I am only left with characters that follow the first few letters?

For example: Original - "Mark_Mathworks_3088" change to "Mathworks_3088"? In the example I want to remove "Mark_", I have few files with "Mark" in the front and others with different names such as - "Nat", "Watt", & "Rick" which I want to remove as well.

What would be a correct code to make this work?

Answer 1

[Image Analyst]

Get the string first from your structure or cell array.

filename = dirListing.name; % if you got by using dir() function or
filename = cellArray{index}; % if it's in a cell array.

Then find the underline and get from there on:

underlineLocation = strfind(filename, '_');
filename = filename(underlineLocation + 1 : end);

[Yash Bhakta]

I am not familiar with Matlab, Can you please show the full explanation of the code and how to write it.

[Image Analyst]

That is how you write it. Those are actual lines of MATLAB code. If you don't know the first thing about MATLAB, take the 2 hour training course here: https://matlabacademy.mathworks.com/

You'd do something like (untested):

inputFolder = pwd; % Wherever you want.
outputFolder = pwd; % Wherever you want.  Can be the same as inputFolder if you want.
dirListing = dir(fullfile(inputFolder, '*.m'));
for k = 1 : length(dirListing)
  baseFileName = dirListing(k).name;
  underlineLocation = strfind(baseFileName, '_');
  if ~isempty(underlineLocation)
    outputBaseFileName = baseFileName(underlineLocation + 1 : end);
    inputFileName = fullfile(inputFolder, baseFileName);
    outputFileName = fullfile(outputFolder, outputBaseFileName);
    fprintf('Ranaming %s to %s.\n', baseFileName, outputFileName);
    if isequal(inputFolder, outputFolder)
      % Rename in place.
      movefile(inputFileName, outputFileName);
    else
      % Make copy in other folder.
      copyfile(inputFileName, outputFileName);
    end
  end
end

[Yash Bhakta]

The files are not in .m format. They are in folder with different file types. Some are .docx, .pdf, and some in .text format.

[Image Analyst]

So, simply change the .m to .docx, .pdf, .*, or whatever in the file pattern in the call to dir(). It doesn't matter to the rest of code.

[Kaitlynn Conway]

I tried using this code to shorten the name of my files. I just wanted to keep the first 21 letters of the file name and save the new files in a new folder.

It did all of that correctly, except when I ran the program, the files it saved in the new folder werent tifs anymore. How do I rename my files without making sure the content of the files remain unchanged?

clc 
clear variables
close all

inputFolder = ('D:\Hytrel Testing\Hytrel EL217-5-2'); % Wherever you want.
outputFolder = ('D:\Hytrel Testing\Hytrel EL217-5-2\Renamed_Files'); % Wherever you want.  Can be the same as inputFolder if you want.
dirListing = dir(fullfile(inputFolder, '*.tif'));
for k = 1 : length(dirListing)
  baseFileName = dirListing(k).name;
  %underlineLocation = strfind(baseFileName, '_');
  if ~isempty(baseFileName)
    outputBaseFileName = baseFileName(1 : 21);
    inputFileName = fullfile(inputFolder, baseFileName);
    outputFileName = fullfile(outputFolder, outputBaseFileName);
    fprintf('Ranaming %s to %s.\n', baseFileName, outputFileName);
    if isequal(inputFolder, outputFolder)
      % Rename in place.
      movefile(inputFileName, outputFileName);
    else
      % Make copy in other folder.
      copyfile(inputFileName, outputFileName);
    end
  end
end