Help create a DTFM decode function

Need help create a code that can decode the ringphones. When I run function lab 9. i will get the answer such as

>> lab9

s1: 123456789*0# is O.K.

s2: 123456789*0# is O.K.

s3: 123456789*0# is O.K.

s4: 123456789*0# is O.K.

s5: 123456789*0# is O.K.

s6: 123456789*0# is O.K.

complete this code:

function str=dtmfcode(s,fs)

function lab9
%
%  Make sure you download all the test files s1.wav -> s8.wav

nFiles = 6;

for i = 1:nFiles
    fileName = ['s' num2str(i)];
    [s, fs] = audioread(fileName);
    num = round(32768 * s(end-12:end));
    indx = find(num);
    num = num(indx(1):end);
    str = char(48 + num);
    
    out = dtmfdecode(s, fs);

    fprintf(1, '%s: ', fileName)
    if (~isempty(out))
        if (strcmp(out(:), str(:)))
            fprintf(1, '%s is O.K.\n', out);
        else
            fprintf(1, 'Got %s instead of %s\n', out, str);
        end
    else
        disp('Empty');
    end
end

return