fileID has a limit?

I'm trying to generate txt files from combinations, using the nchoosek command. I have generated 2047 combinations, but when I try to write the combinations on a txt file, only 196 files are generated and then the error "??? Error using ==> fprintf Invalid file identifier. Use fopen to generate a valid file identifier." is triggered. Can anyone help me? Here is a piece of code.

for line=1:num_comb %num_comb = total of combinations

    str = sprintf('combinacao%d.txt',line); % name of the txt file changing on every combination 
    for column=1:n
        if matriz(line,column) ~= 0 %matrix 'matriz' has a combination in each line

            fid=fopen(str,'a');

            for rl=1:count_size(matriz(line,column))+1

                fprintf(fid,'%s \r\n',matriz_field{matriz(line,colmun),rl}); %matrix 'matriz_field' has the information to be written using as index the content of 'matriz' matrix

            end

            fclose=(fid);
        end

    end
end

Answer 1

[Walter Roberson]

fclose=(fid); should be fclose(fid);

[Rodrigo Lima]

Thanks, it worked this time!