How to remove a pattern from filename in Matlab - matlab

Question

I'd like to remove '-2' from the filenames looking like this:
EID-NFBSS-2FE454B7-2_TD.eeg
EID-NFBSS-2FE454B7-2_TD.vhdr
EID-NFBSS-2FE454B7-2_TD.vmrk
EID-NFBSS-3B3BF9FA-2_BU.eeg
EID-NFBSS-2FE454B7-2_PO.txt
So as you may see the names of the files are different and there are different kind of extensions as well. All what I want to do is remove '-2' from all of the filenames. I was trying use this:
pattern = '-2';
replacement = '';
regexprep(filename,pattern,replacement)
and I got the results in the console, but after many attempts I have no idea how to 'say' to MATLAB switch the filnames in the same location.

Answer 1

#excaza hit it right on the money. You'll have to probe your desired directory for a list of files via dir, then loop through each filename and remove any occurrences of -2, then use movefile to rename the file, and delete to delete the old file.
Something like this comes to mind:
%// Get all files in this directory
d = fullfile('path', 'to', 'folder', 'here');
directory = dir(d);
%// For each file in this directory...
for ii = 1 : numel(directory)
%// Get the relative filename
name = directory(ii).name;
%// Replace any instances of -2 with nothing
name_after = regexprep(name, '-2', '');
%// If the string has changed after this...
if ~strcmpi(name, name_after)
%// Get the absolute path to both the original file and
%// the new file name
fullname = fullfile(directory, name);
fullname_after = fullfile(directory, name_after);
%// Create the new file
movefile(fullname, fullname_after);
%// Delete the old file
delete(fullname);
end
end
The logic behind this is quite simple. First, the string d determines the directory where you want to search for files. fullfile is used to construct your path by parts. The reason why this is important is because this allows the code to be platform agnostic. The delineation to separate between directories is different between operating systems. For example, in Windows the character is \ while on Mac OS and Linux, it's /. I don't know which platform you're running so fullfile is going to be useful here. Simply take each part of your directory and put them in as separate strings into fullfile.
Now, use dir to find all files in this directory of your choice. Replace the /path/to/folder/here with your desired path. Next, we iterate over all of the files. For each file, we get the relative filename. dir contains information about each file, and the field you want that is most important is the name attribute. However, this attribute is relative, which means that only the filename itself, without the full path to where this file is stored is given. After, we use regexprep as you have already done to replace any instances of -2 with nothing.
The next point is important. After we try and change the filename, if the file isn't the same, we need to create a new file by simply copying the old file to a new file of the changed name and we delete the old file. The function fullfile here helps establish absolute paths to where your file is located in the off-chance that are you running this script in a directory that doesn't include the files you're looking for.
We use fullfile to find the absolute paths to both the old and new file, use movefile to create the new file and delete to delete the old file.