A data file called “mathfile.dat” stores three characters on each line: an operand (a single digit number), an operator (a one character operator, such as +, -, /, \\, *, ^), and then another operand (a single digit number). For example, it might look like this:

Ch9Ex16.m

% Read in math operations from a data file,

% perform the operation and print the result

fid = fopen('mathfile.dat');

if fid == -1

 disp('File open not successful')

else

 while feof(fid) == 0

 % Get operand, operator, operand

 % and perform the operation!

 aline = fgetl(fid);

 res = eval(aline);

 fprintf('%s = %d\n', aline, res)

 end

 closeresult = fclose(fid);

 if closeresult == 0

 disp('File close successful')

 else

 disp('File close not successful')

 end 

end