% !/bin/cp fib.m safe % !/bin/rm *.* % !/bin/mv safe fib.m % Clean user's function from some known jailbreaking mechanisms functions={'!','feval','eval','str2func','str2num','regex','system','dos','unix','perl','assert','fopen','write','save','setenv','path','please','for','if','while','switch','round','roundn','fix','ceil','char','floor','\.','^','power'}; fid = fopen('fib.m'); st = char(fread(fid)'); for n = 1:numel(functions) st = regexprep(st, functions{n}, 'error(''No fancy functions!''); %','ignorecase'); end st = regexprep(st, 'function', 'error(''No fancy functions!''); %','ignorecase',2); fclose(fid); fid = fopen('fib.m' , 'w'); fwrite(fid,st); fclose(fid);

n = 1:5; f = [1 1 2 3 5]; assert(isequal(fib(n),f))

n = 7 : 10; f = [13 21 34 55]; assert(isequal(fib(n),f))

n = 20 : 22; f = [ 6765 10946 17711]; assert(isequal(fib(n),f))