Data Organization Programming Assignment 1

CS 241L - Data Organization

Programming Assignment 1
Total points: 100

In this project, you will work in the Linux command line to write your first
C programs. Follow the steps outlined below to complete your project and be
sure to see the Grading Rubric provided at the end of this file as guide for
completing the assignment.
Part 0: Extract files from tarball
1. The programming assignment is given to you as a compressed tarball. In
order to extract the files from this tarball use the command tar -xvf
programming assignment 1.tar.gz. This will create a folder with name
‘Programming Assignment 1’ in your current directory.
Part 1: Redirecting output from stdout to a file
1. Connect to a CS machine (moons.cs.unm.edu or b146 lab machines) using
ssh with PuTTY, NoMachine, or the Terminal (Mac or Linux).
2. When you login, type pwd. You should be in your home directory which
has the same name as your CS account username.
3. Create a directory called project1 in your home directory.
4. Go to the project1 directory using cd.
5. List contents of project1 using ls. It should have no files and no subdirectories.
6. Open a new file called shapes.c with your editor.
7. shapes.c will contain the source code of a C program that prints the
shapes in Figure 1:
Hint: Modify the hello world.c file to print these shapes provided to
you.
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Figure 1: These shapes are in the file shapes.out provided to you.
8. Use the command:
gcc -Wall -pedantic -ansi shapes.c
to compile and create an executable called a.out. It should compile without warnings or errors. If there are warnings or errors, edit your source
file.
9. Look into the contents of project1 with ls. Which files are there now?
10. Now use ls with an option to list both details (such as permissions, owner
and group), and hidden files. What are these options? (Hint: use a dash
and two letters after ls. Which letters are these?)
11. ls shows the contents of project1 on the terminal screen. This is called
the standard output stream, or stdout . You can redirect this output to
a file if you would like to save it using the symbol > . Run the command:
ls > ls.out
12. Now type ls and look at the list of files in stdout . You should see ls.out
listed now.
13. Open ls.out. What are its contents? They should list the contents of
running ls. Notice that ls.out is also included.
14. Now run the executable typing in the prompt:
./a.out
15. You should see on the screen the output of the shapes.c program. If you
do not see the shapes as displayed above, edit your source file.
16. Redirect output of C program. Combine the steps in (11) and (14) above
to redirect the output of the shapes program to a file called myshapes.out.
What do you observe on the terminal screen?
17. Type ls in the command prompt. Which files are there now? Update the
ls.out file using redirection (>) again.
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Part 2: ASCII and data types
1. The characters printed in Part 1 are ASCII characters with given values
(see table from our lecture slides). The 7 characters printed in shapes.out
are - _ / \ : + *
What are the decimal values of the above characters?
2. Create a copy of your C program shapes.c with cp and name it newshapes.c.
3. Modify newshapes.c so that it prints the same image as in shapes.out
but uses different characters. The ASCII decimal values of the new characters are the decimal values of the original characters (listed above in 1)
minus 9. For instance, - has a 45 value in ASCII, so the new character
would be the one whose value is 36. This new character will be printed
where all - are placed originally in shapes.out.
Hints:
- Make -9 a constant in your program called SHIFT using #define or
const
- Keep your program clear and concise by declaring new variables when
needed.
4. Compile newshapes.c with the -Wall -pedantic -ansi options.
5. Run your new a.out executable and redirect its output to a file called
mynewshapes.out. Note that an output file is not provided to you for comparison.
What to submit:
Submit a tarball to Canvas with name <Your-Student ID> 1.tar.gz containing the following files:
ls.out
shapes.c
myshapes.out
newshapes.c
mynewshapes.out
The command for this is tar -czvf <Your-Student ID> 1.tar.gz ls.out
shapes.c myshapes.out newshapes.c mynewshapes.out.
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Grading Rubric:
If any of your C programs do not compile with the -ansi -pedantic -Wall
options without errors or warnings the points given for the assignment will be
zero. Otherwise the following rubric will be used:
+ 7 pt: Your C programs start with a comment on top of the file with
your name and description of the programs
+ 10 pts: Your C programs follow the class coding standards
+ 10 pts: You have submitted the required files separately (you did not
combine them into a single zip file).
+ 27 pts: Your output file myshapes.out passes a diff test when compared with the output file shapes.out that was provided to you.
+ 27 pts: Your output file mynewshapes.out passes a diff test when
compared with an output file that only the grader has access to.
+ 19 pts: Your program newshapes.c produces the correct output when
the grader changes the value SHIFT to a different number where it is
declared or defined.
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