MATLAB: Rename files using matlab

file rename

Hello all,
I have a folder on my desktop that has 10 text files as following:
A.txt
Abgd.txt
B.txt
Bbgd.txt
C.txt
Cbgd.txt
S.txt
Sbgd.txt
std.txt
stdbgd.txt
I want to write a code that the changes the names of the first 8 files. I want to rename these files and add an underline (i.e. '_') after the first letterof each file. So my output should look like this:
A_.txt
A_bgd.txt
B_.txt
B_bgd.txt
C_.txt
C_bgd.txt
S_.txt
S_bgd.txt
Here is what I have done so far:
clear all; clc;
d = 'C:\Users\krraz\Desktop\Day13\*.txt';
oldnames = dir(d);
oldnames = {oldnames(~[oldnames.isdir]).name};
L = length(oldnames);
oldnames = oldnames(1:L-2);
points = oldnames(1:2:end);
points = cellfun(@(x) x(1:1), points, 'UniformOutput', false);
strr = '_.txt'; strr = string(strr);
for n = 1:numel(points)
formatSpec = '%1$s%2$s';
points{n} = sprintf(formatSpec,points{n},strr);
end
bgds = oldnames(2:2:end);
bgds = cellfun(@(x) x(1:1), bgds, 'UniformOutput', false);
strr = '_bgd.txt'; strr = string(strr);
for n = 1:numel(bgds)
formatSpec = '%1$s%2$s';
bgds{n} = sprintf(formatSpec,bgds{n},strr);
end
newnames = [points bgds];
newnames = sort(newnames);
for j=1:numel(oldnames)
movefile(d,newnames{j},'f');
end
But when I run my code, It generates a new folder on my desktop and doesn't change the names of the files. What am I doing wrong?
Any insight will be appreciated.

Best Answer

You have
d = 'C:\Users\krraz\Desktop\Day13\*.txt';
which includes the *.txt . You do not change d in your code. Later you have
movefile(d,newnames{j},'f');
but d still has the *.txt part, so it is going to move all the text files instead of moving one at a time.
projectdir = 'C:\Users\krraz\Desktop\Day13';
dinfo = dir( fullfile(projectdir, '*.txt') );
oldnames = {dinfo.name};
unwanted = cellfun(@isempty, regexp(oldnames, '^[A-Z][^_].*') );
oldnames(unwanted) = [];
newnames = regexprep(oldnames, '^(.)', '$1_');
for K = 1 : length(oldnames)
movefile( fullfile(projectdir, oldnames{K}), fullfile(projectdir, newnames{K}) );
end