IT 244: Introduction to Linux/Unix - Rules for Homework Scripts

IT 244: Introduction to Linux/Unix
Rules for Homework Scripts

You need to create a directory for each homework assignment
This directory must be inside your hw directory
And the hw directory must be inside your it244 directory
The homework directory name will begin with "hw" followed by the number of the assignment
The filename for each homework shell script must
- Begin with "hw"
- Followed by the homework number
- Followed by ".sh"
So the script for homework 3 should be named hw3.sh
And the script should be inside an hw3 directory
Each step in the homework MUST labeled with a Step number comment
The comment must have the word "Step" followed by step number
So, the line before the Unix commands that perform Step 1 should read
```
# Step 1
```
And the line before the Unix commands that performs Step 2 should read
```
# Step 2 
```
It should be "Step" not "step"
There should also be a blank line before each Step comment but not after it
The blank line helps me see where the commands for each step ends
There must be no blank lines between the Unix commands for each step

Let's look at an example
If you would like to see a video demonstrating the proper format for this example click here
Let's say that homework 99 asks you to do the following:
1. Go to your home directory
  Run a command that shows that you are in your home directory
2. List the contents of your directory
3. List the contents of /home/ghoffman/course_files/it244_files
For this assignment you would have to create an hw99 directory inside your hw directory
Inside this hw99 directory you would create the file hw99.sh

Here is the text of the file

# Step 1
cd
pwd

# Step 2
ls

# Step 3
ls /home/ghoffman/course_files/it244_files

There are a number of common mistakes that student make with their homework scripts
These mistakes make it hard for me to score the assignments
If you make any of the mistakes listed below you will lose points

Never use one of the following commands inside your homework script
- more or less
- Editors like nano, vi, vim or emacs
- man or info
You will never need to use these commands in a homework script
Using these commands will make it harder for me to score your homework

You must have a Step comment before the commands for each Step
That does not mean a Step comment before each command
So if a Step requires more than one command ...
you only need a comment at the beginning of the Step
For example if Step 4 asked you to
- Go to your home directory
- List the contents of your home directory
You should write this
```
# Step 4
cd
ls
```
Not this
```
# Step 4
cd

# Step 5
ls
```

The following is wrong

it244gh@vm75:~$ # Step 1
it244gh@vm75:~$ cd ~
it244gh@vm75:~$ pwd
/home/it244gh

Properly formatted Step comments are important
So I have created a shell script which will check your Step comments in a homework script
This script looks for each of the required Step comments
It prints an error message if it cannot find them
To run this script, go to the directory ~ghoffman/it244_test
The name of the script is step_comment_check.sh

The script requires two arguments

$ ~ghoffman/it244_test/step_comment_check.sh
Usage: step_comment_check.sh USERNAME HW_NUMBER

your Unix username and the homework number

$ ./step_comment_check.sh ghoffman 4
# Step 1
# Step 2
# Step 3
# Step 4
# Step 5
# Step 6
# Step 7
# Step 8
# Step 9
# Step 10

If your script is missing a comment you will get an error message

$ ./step_comment_check.sh ghoffman 3
# Step 1
# Step 2
Could not find # Step 3
Could not find # Step 4
Could not find # Step 5
...

The purpose of step_comment_check.sh is to check for Step comments
But it also detects two other problems that cause a student to lose points
- Homework scripts in the wrong directory
- Empty or incomplete homework scripts
When it is time to score homework assignments I run a collection script
This script copies files from each student's directory for that assignment
It often happens that a students create the homework script in the wrong directory
This means my script cannot collect it and the student receives a 0 for the assignment
step_comment_check.sh knows which directory is supposed to contain the script
It will print an error if it cannot find the file
Students sometimes leave empty or incomplete scripts in their homework directory
The step checking script will also catch these errors
Because it will not be able to find the required Step comments