You should pass file names to the function and/or a base path.
filenames = {'a.txt', 'b.txt'} ; % Cell array of file names.
results = myFunction(filenames) ;
with myFunction.m as follows :
function results = myFunction(filenames)
for k = 1 : length(filenames)
name = filenames{k} ;
% .. do something, e.g. FOPEN + read, CSVREAD, DLMREAD
% and define results.
end
end
