How to delete a string in multiple files by using eraseBetween (R2019a)

Hello,

I am trying without success to delete a specific string (everything between xmln= and the next space) in multiple text files (xml files) by using the function eraseBetween. The files would then be moved to a new folder. The code so far is below. Any help welcome.

modified_xml = fullfile(pwd, 'modified_xml')    
if exist([pwd '\modified_xml'])~=7              
	mkdir(modified_xml);                        
end


InputOldFiles = dir(fullfile('*.xml'));          
OldFilesNames = {InputOldFiles.name};            

for k = 1 : length(InputOldFiles)
	OldFiles = OldFilesNames{k};
	
    FID = fopen(OldFiles, 'r');
    if FID == -1, error('Cannot open file'), end
    
    % Delete specific string (everything between xmlns= and the next empty space)
    text = textscan(FID, '%s', 'delimiter', '\n', 'whitespace', '');
    new_text = eraseBetween(text,"xmlns="," ");

    NewFiles = fopen(OldFiles, 'w');
    if NewFiles == -1, error('Cannot open file'), end
    
    % Save the file 
    fprintf(NewFiles, '%s\n', new_text{:});
    fclose(NewFiles);
    
    % Copy the files
    copyfile(OldFiles, NewFiles);             
end