Laboratory Assignment 0
                               CS 340d
                         Unique Number: 50960
                             Spring, 2019

                       Given:  January 28, 2019
                        Due:  February 11, 2019

This laboratory concerns duplicating much of the functionality of the
Unix "wc" command.  In addition, this laboratory concerns adding
functionality beyond that of the standard "wc" command.


General Comment

Before we describe this laboratory assignment, we describe our
philosophy for our all laboratory assignments and for many of our
homework assignments.  We expect our programs to implement their
requirements with mathematical precision, but programs are generally
specified with natural language.  To this point in your education,
most programming assignments have included some description of what
program you should write, and then, you are expected to interpret the
documentation and produce a result.  It requires tremendous care and
precision to write a precise description of any computation in a
natural language -- it is certainly beyond our ability to write
completely precise, natural-language specifications.

We would like to write mathematical specifications, but that would
require us learn mathematics for most of semester.  As a community of
software developers, this approach would be extremely valuable where
it can be deployed, but it is not yet a mature discipline.  Even so,
we will sometimes refer to programs that can be specified formally.


Laboratory Requirements

This laboratory involves duplicating some of the functionality of the
"wc" command.  Your solution needs to work only on byte-oriented input
streams or files.  Note, your program should also work on binary
files.  You should name your "wc" command "mywc".

Your "mywc" command should accept the command-line arguments "-c",
"-l", "-w" as specified in the "wc" command, and also two extra flags,
the "-C" (the uppercase "C") and the "-N" (the uppercase "N") options.

The "-C" option should eliminate the remainder single-line C-language
comment strings.  Single-line, C-language comments start with the
string "//" (two "/" characters) and extend to the end of the line;
however, the end-of-line (<LF>) characters should not be elided.  So,
really, the specification for "-C" is:

   sed 's://.*$::g'  |  wc <options>

Your "mywc" program must also respond to the "-N" flag by printing the
number of decimal numbers in the input.  What is a decimal number?  It
is any string of adjacent digits (characters "0", "1", ... "9").

Your "mywc" program only needs to accept input from STDIN and print to
STDOUT.  Thus, parsing filename (command-line) arguments is not
required.

Here, we include some typical text that might help.  The number of
characters returned should be equal to the length of the file or
input.  The number of lines should be equal to the number of line feed
characters contained in the file.  The number of words should be equal
to the groups of characters separated by spaces, tabs, line feeds, and
carriage returns.  But, instead of reading this, you should read the
"wc" manual entry; try "man wc" at the command-line prompt.

But, the real specification is what the Linux version of "wc" does on
the departmental Linux computers.  Extra credit may be awarded if you
find a discrepancy of some kind in the Linux, FreeBSD, or MacOS
commands.  What is a discrepancy?  Absolutely any input file or stream
that causes your "mywc" version to produce a correct result that is
different than the UTCS Linux computers.  Now, if you can argue to the
class that even though your implementation is inconsistent with the
UTCS Linux result, that your result is correct -- then you may have
found a Linux bug!  Bugs of this kind are always worth extra credit.

Be careful.  Think about how the various flags might interact.
Should the "-C" take precedence over the "-N" flag?  Or should it
be the other way?  You will need to make a decision -- defend your
decision.

For more "sed" details", see:  http://www.grymoire.com/Unix/Sed.html
and see:  http://sed.sourceforge.net/sed1line.txt .  There are many
more documents describing the regular-expression language.


Laboratory Documentation

Finally, for the writing component, you need to include in your
solution program a 60-line to 90-line description of your "mywc"
command. This description should be included as a C-language comment
that begins with a line containing only "/*" and ends with a line
containing only " */", and written in the (approximate) format of
a typical Linux manual entry.  Remember, this class carries a writing
flag, and this kind of summary will be required for all of the class
laboratory assignments.


Grading

You laboratory will be graded as with the following weights:

  70% - Functioning of your "wc" implementation as specified above
  30% - Written description of your "wc" command.

Be careful with what you write.  We will be grading the functioning of
your program on several hundred files.  And, we will carefully read
your documentation, looking for problems (grammar, spelling, run-on
sentences, tense agreement, etc.) -- errors will lower your grade.


Turn-in

Prior to the due date, we will post submission instructions.