Scripting 3: Writing Your Own Scripts

The report template for this lab can be found here (Links to an external site.). I recommend opening the instructions and the report template in Firefox in your VM to enable easy copy-and-paste.

Enhanced addpermplus.sh

Copy addpermplus.sh to permplus.sh and add the ability to add or remove permissions. This is done by adding another argument to the script as shown below:

./permplus.sh

Here, the first argument is the target set of permission bits (user, group, other, or all). The second argument is whether we are adding (a) or removing (r) the permission. The third is what permission (read, write, or execute). The fourth argument is a file or directory to modify.

Add checks for each of the arguments

the first argument value is only u, g, o or a

the second argument value is only a or r

the third argument value is only r, w, or x

the fourth argument is a valid name (i.e. a valid file or directory)

What do you need to check for? Justify your choice. Hint: These checks will augment the existing check in the if block above.

Be sure to issue meaningful errors.

Test your script and document the results. You should include at least one successful test case, and one test case to trigger each error condition you check for in the script.

1. Include a screenshot of the script running correctly

2. Include a screenshot of the script running in an error condition

3. Include your code for the script. Please ensure that the code you paste here uses a monospaced font and is white.

Menu-driven Scripting

Often times, it is helpful to provide a set of menus for a script instead of putting all options as command-line arguments. You will need to think carefully about how to handle input to make the experience as user-friendly as possible. You will also need to think about how you might prompt users for additional input for menu options that require it. In this part of the assignment, you will generate the skeleton for a menu-driven script. Below is the "navigation map" for the script. Script3-

The following are the requirements that the script must satisfy.

The root should instead provide a quit option Each level should provide an option to go back to the previous level if not at the "root".

If you choose to use letters as your menu selection options, then the choices must be case-insensitive (i.e. typing A and a should be the same thing)

For each of the leaf nodes in the map, create a function and call that function when that option is chosen. For example, if Option A.3 is chosen, then a function corresponding to Option A.3 is called. The functions in this case should just have an echo statement announcing the chosen option and then returning to the menu.

At least two leaf nodes must collect additional user input and incorporate that into the output of the function

4. Include a screenshot of the script running correctly

5. Include a screenshot of the script running in an error condition

6. Include your code for the script. Please ensure that the code you paste here uses a monospaced font and is white. Note: This would be a great script to convert into a "container management" script that does some of the following things:

Create new container (asking for name, image to use, and IP address) since you will be creating a number of containers this semester

Start and stop containers (asking for container name)

Delete containers (asking for container name), although here I would ask for additional confirmation first

Take and restore snapshots from containers

Push and pull files from containers

Automating Repetitive Tasks: Account Creation

In order to repeatedly test this script repeatedly, you either need to figure out how to delete users that have been created (and write a script to do that), or investigate taking snapshots that you can revert to. If you go the snapshot route, I would suggest finishing your current round of code edits, take a snapshot of the scripting container, running the code, then reverting the container state. You can find more details about LXD snapshot management here. Personally, I recommend the following methodology for testing.

Recommended method for testing:

Create your add-user.sh script in the VM (not in a container)

Create a new container called testing by running the following command in the VM

lxc launch ubuntu:18.04 testing

Copy the script into the container and then connect to the container by running the following command in the VM

lxc file push add-user.sh testing/root/add-user.sh

lxc file push users.csv testing/root/users.csv

lxc exec testing -- /bin/bash

Run the script and verify that the results are correct by running the following command in the testing container

./add-user.sh users.csv

If the results are correct, copy the requested files to the VM and collect any requested screenshots by running the following command in the VM

lxc file pull testing/rootew-users.dat new-users.dat

If incorrect, edit your script in the VM and delete the testing container by running the following commands in the VM then go back to the beginning of this section

lxc stop testing

lxc delete testing

Add User Script

You will create a script named add-user.sh to create new users on the system from a specially formatted file. The data is formatted as a specially formatted text file called a CSV (comma separated values) file. Normal capitalization will be used (i.e. capital letters for the first letter of each part of the name). Your delimiter is the same as the one produced by making a CSV file from an Excel spreadsheet (or equivalent). Your script will read the exported .csv file, change all uppercase letters to lowercase and form a userid with the following algorithm:

Skip the first line that is a header that defines each field.

The userid is to use up to the first 6 characters of the last name concatenated with the first 2 characters of the first name. For example, if the first name is Alan and the last name is Turing, then the username should be turingal

Use the adduser command to create the accounts.

Generate a random password that will be recorded and sent to the user.

Use any method you want to generate a random password. Hint: There are many ways to easily generate a random password. Google will be your friend here.

Record the generated username and password in a file called new-users.dat in the following format:

, ,

Document your code and the successful testing of it. You will need to have error checking code and test cases for each error condition as well as a successful test case shown below. Use the CSV file shown below.

"Last Name","First Name"

Moyer,Thomas

Williams,Trevon

Shah,Zarna

Hall,Jordan

Turing,Alan

Goble,Katherine

Jackson,Mary

Vaughan,Dorothy

Lovelace,Ada

Hopper,Grace

Goldwasser,Shafi

You can use a combination of sed, bash script, awk, and whatever other commands you need to automate the task. Include a screenshot of the script running correctly

Include a screenshot of the script running in an error condition

Include your code for the script. Please ensure that the code you paste here uses a monospaced font and is white.

Template

Scripting 3: Writing Your Own Scripts

Name

Enhanced addpermplus.sh

1. Include a screenshot of the script running correctly

Paste your screenshot here

2. Include a screenshot of the script running in an error condition

Paste your screenshot here

3. Include your code for the script. Please ensure that the code you paste here uses a monospaced font and is white.

Menu-driven Scripting

4. Include a screenshot of the script running correctly

Paste your screenshot here

5. Include a screenshot of the script running in an error condition

Paste your screenshot here

6. Include your code for the script. Please ensure that the code you paste here uses a monospaced font and is white.

Automating Repetitive Tasks: Account Creation

7. Include a screenshot of the script running correctly

Paste your screenshot here

8. Include a screenshot of the script running in an error condition

Paste your screenshot here

9. Include your code for the script. Please ensure that the code you paste here uses a monospaced font and is white.