For this assignment, you will be writing test cases for your next
assignment.  As usual, the instructions for the next assignment are
in next-README.

For this assignment, we have created compiled binaries (in
/usr/local/l2p/rot_matrix/  where rotateMatrix is correct,
and the numbered ones are each broken in some way).

As with 09_testing2, you will write a file called tests.txt,
which will list the command line arguments you want to use to
run the programs.   However, unlike 09_testing2, you will
also want to create a wide variety of input files.  You can
name them anything you want, as long as you save them in the
current (26_tests_matrix_input) directory, and submit them
along with tests.txt.

As usual, we have provided run_all.sh

Hint 1: think about various error cases that the programmer
might have forgotten!

Hint 2: The trickiest of these is one in which the programmer
did not pay attention to a rather subtle, but common mistake
pointed out in your reading titled 'Reading a File'!

Hint 3:  If you find yourself needing to create an input
file with non-typable/non-printable characters in it,
you will want to do a few things.

First, (after you have the file you want to edit open), you
will want to force emacs to change the encoding it uses
(so that it won't try to rewrite things in Unicode, for example):

M-x revert-buffer-with-coding-system
raw-text

Once you have done this, you can do

M-x hexl-mode

to put emacs in hex editor mode.

Then you will see hex values on the left, and their printable
interpreations (or . for non-printable characters) on the right.
Move the point to where you want to put a particular value, and do

C-M-x

then type the hex value (one byte, so two hex digits) that you want,
and hit enter.  It will overwrite the current character with that value.
Then you can save the file.