Make changes to multiple files simultaneously?

I need to add one line of code to 100 files, is there any way I can modify all of them at once (without changing them individually?)

Thanks.

Answer 1

[dpb]

Notepad++ has a feature that may work if you can make the replacement with a [regexp] expression as a substitution.

Alternatively, there are editors with batch-capable commands that can operate in batch file mode in a for...each mode on a file list.

Or, you can write a Matlab script that does the job -- if the line goes in a fixed location like at the end, it's pretty trivial if the files are either named with a well-defined name that is usable wildcard pattern or are all in a given location --

Alert -- air code, test thoroughly before destroying anything by having backups!!!

nL=100;             % target line number in file
L="Your new text";  % the text to add/insert
d=dir(fullfile('yourfolder','yourfile*wildcardname.ext'));  % get the list of files
for i=1:numel(d)
  fn=fullfile(d(i).folder,d(i).name);                       % the fully-qualifie fn
  F=readlines(fn);                                          % in memory as string array
  F=[F(1:nL);L;F(nL+1:end)];                                % insert the line where wanted
  writematrix(F,fn)                                         % rewrite modified file
end

The above overwrites the original file, obviously you can modify the filename before writing to avoid that...

[Zi]

@dpb Hi thanks for the response.

There is an error with F = F(; ; ;) line: "invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters"

I changed the semicolons with comma, got the following error:

"Error using readlines. Not enough input arguments."

Your advice on it is highly appreciated.

[dpb]

F=[F(1:nL);L;F(nL+1:end)];  

[Stephen23]

F=readlines(fn);

[dpb]

Thanks, @Stephen23. I started with the fullfile() in there and then realized needed it again and moved it -- but then failed to put the variable back in its place...I did say was air code... :)