Assignment 1 Text formatter

Software Engineering 265
Software Development Methods

Assignment 1

Programming environment
For this assignment you must ensure your work executes correctly on the Linux
machines in ELW B238. You are welcome to work on your own laptops and
desktops; if you do this, give yourself a few days before the due date to iron out any
bugs in the C program you have uploaded to the BSEng machines. (Bugs in this kind
of programming tend to be platform specific, and something that works perfectly at
home may end up crashing on a different hardware configuration.)

Objectives of this assignment
• Understand a problem description, along with the role used by sampleinput
and output for providing such a description.
• Use the C programming language to write the first implementation of aSENG
265 text formatter named “sengfmt” (and do this without using dynamic
memory).
• Use Gitlab to manage changes in your source code and annotatethe
evolution of your solution with “messages” provided during commits.
• Test your code against the ten provided test cases.
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This assignment: “sengfmt.c”
You are to write a C program that inputs lines of text files, reads formatting options
contained within those text files, and then outputs the text where each line has the
appropriate width, indenting, etc. as indicated by the formatting options. For
example, here is one such file contained in the “test” subdirectory at
/home/seng265/A1/test/ (“in04.txt”):
This particular file contains one formatting option (“?width 30”) which indicates
that the following text must be formatted such that each line contains at most 30
characters. The formatting program also concatenates the lines of a paragraph
together in order to eliminate unnecessary white space. The resulting output
(stored in “out04.txt”) looks like this:
With your completed “sengfmt” program, the input would be transformed into the
output via the following UNIX command:
where the file “out04.txt” would be placed in your current directory. To compare the
output produced by sengfmt with what is expected, you can use the Unix “diff”
command as shown below (assuming you’re still in the same directory as when you
executed the command above):
Note that “diff” is much more reliable than your own eyes!
For this first assignment there are only four formatting commands:
• ?width width: Each line following the command will be formatted such that
there is never more than width characters in each line. The original
whitespace in the input text need not necessarily be preserved (i.e., single
at least one line, there is
plenty
of
white space that needs to be
eliminated
from the original
text file.
are enough characters here to
?width 30
While there
fill
While there are enough
characters here to fill at
least one line, there is
plenty of white space that
needs to be eliminated from
the original text file.
% ./sengfmt /home/seng265/A1/test/in04.txt ./out04.txt
% diff -b /home/seng265/A1/test/out04.txt ./out04.txt
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spaces are used to separate words in the output). If this command does not
appear in the input file, then the input text is not transformed in the output.
• ?mrgn left: Each line following the command will be indented left spaces from
the left-­­hand margin. Note that this indentation must be included in the page
width. If this command does not appear in the input file, then the value of left
is 0 (zero).
• ?fmt [off | on]: This is used to turn formatting on and off. If the command
appears with “off”, then all text below the command up to the next “?fmt”
command is output without being formatted. If the command appears with
“on”, then all text below the command up to the next “?fmt” command is
output with as many words as will fill the given page width. (It may be that
there is no “?fmt” command following, in which case the choice of “on” or
“off” is used for the remaining input text.)
There is some default behavior expected. (Some details from the previous bullet
points are repeated below.)
• If no “?width” command appears, the default mode is “?fmt off”. In this case
all “?mrgn” commands are ignored.
• If a “?width” command appears, the default mode is “?fmt on”.
• For this first assignment, there will only ever be one “?width” or “?mrgn”
command in an input file, and these will appear at the top of the file.
• For this first assignment, you can assume that all test files will have page
widths that are much greater than left margins (e.g., there will not be a
combination such no as “?width 30” and “?mrgn 40”).
• There is no limit to the number of “?fmt” commands that can appear within
an input file.
Exercises for this assignment
1. If you have not already done so, ensure your Gitlab project is checked out
(using ‘git clone’) from the repository. Within the project check if you have
an “A1” subdirectory. Create one if you don’t. Ensure all directories and
program files you create are placed under version control of Gitlab. (You
need not add the test directory to version control unless you wish to do so.)
2. Write your program. Amongst other tasks you will need to:
• read text input from a file, line by line
• write output to the terminal
• extract substrings from lines produced when reading a file
• create and use arrays in a non-trivial array.
• use the “-ansi” flag when compiling to ensure your code is ANSI
compliant.
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3. Do not use “malloc”, “calloc” or any of the dynamic memory functions. For
this assignment you can assume that the longest input line will have 132
characters, and no input file will have more than 300 lines.
4. Keep all of your code in one file for this assignment. In later assignments we
will use separable compilation features of C.
5. Use the test files to guide your implementation effort. Start with simple cases
(such as those given in this writeup). Refrain from writing the program all at
once, and budget time to anticipate when “things go wrong”.
6. For this assignment you can assume all test inputs will be well-formed (i.e.,
our teaching assistant will not test your submission for handling of input or
for arguments containing errors). Later assignments will specify error
handling as part of the assignment.
What you must submit
• A single C source file named “sengfmt.c” within your subversion repository
“A1” containing a solution to Assignment #1.
• No dynamic memory-­­allocation routines are to be used for Assignment
#1.
Evaluation
Our grading scheme is relatively simple.
Requirement Marks
File sengfmt.c compiles without errors or warnings 1
Code passes the first set of test cases (1 to 3) 3
Code passes the second set of test cases (4 to 5) 2
Code passes the third set of test cases (6 to 7) 2
Code passes the fourth set of test case (8 to 10) 2
Total 10