CSI6204 Scripting Languages: Portfolio Assignment 2 Task 1 Answer

Scripting Languages: Assignment 2.1- Portfolio Task 1

Overview

In this assignment you are required to write four (4) scripts that will demonstrate the extent to which you have understood the shell scripting concepts and practices addressed in Modules 1 to 5 inclusive. Each task is worth five (5) marks for a total assignment value of 20 marks. These portfolio tasks will help you build capacity for implementing the final main assessment.

GENERAL REQUIREMENTS

• Your script will be marked on a standard Linux installation using the bash shell.
• You must only use bash shell script as covered in lectures and workshops.
• Refrain from using non-core commands, tools and utilities in your bash shell scripts. Non-standard bash commands, tools and utilities will not be downloaded and installed by your tutor.
• Ensure each script you write is fully self-contained and is not configured to be dependent on external files, libraries or resources to run.
• Do not use the trap command in any of your scripts.
• Each script you submit must contain your full name and student number at the beginning as code comments.

IMPORTANT NOTES:

• This is an individual assignment only and must not be completed in collaboration with other students
• You may not work with others, acquire code from others, or provide code to others
• Further, you may not post any of the assignment tasks below to a code-development community of any kind seeking solutions or advice
• Nor may you copy and paste or otherwise reproduce code provided by external sources and use it as part of your own solutions
• Where it is found that any of these restrictions have been ignored, academic misconduct proceedings may be initiated
• Please read the checklist below and watch the associated video BEFORE submitting your assignment

Task 1 (5 marks)

Write a script that calculates the sum of three (3) integers passed to it through the command line.

Requirements

• Call the script  calcsum.sh 
• When the script is run, any three (3) integers will be used by your tutor when the script is run on the command line, e.g. ./calcsum.sh 5 10 12. These are example values only, so do not hard-code these into your script. Your tutor will use different values when marking your script.
• The output of the script to the terminal will appear as follows:

The sum of x and x and x is x

where x represents the integers passed to the script when it is run and their calculated sum

• Your script will terminate once this has been done.
• Your script must use bash default variables to hold the passed integers and as arguments in the sum calculation. You may only create a custom variable for the sum of the integers.
• There is no need for data validation in this script; your tutor will enter three (3) integers as required when the script is run.

Task 2 (5 marks)

Write a script that when run, prompts the user to enter a two digit numeric code (integer) that is no less than 20, and no greater than 40.

Requirements:

• Call the script  validint.sh 
• The value input by the user must be validated to ensure that:
  1. It is an integer
  2. It is within the range specified
• In the event that the input entered by the user is invalid, they are to be advised of such and prompted to try again.
• In addition to entering valid values, your tutor will test your validation by also entering:
• Integers outside of the stated range, e.g. 19, 41
• A string, e.g. helloworld
• A null value (by just pressing enter)
• Your script must detect and reject these invalid inputs and prompt the user to try again.
• The input process must continue until a valid two digit numeric code is entered. Do not allow the script to terminate until a valid two digit numeric code has been entered by the user.
• Once a valid two digit numeric code has been entered by the user, echo a message to the screen that a valid input has been made and then terminate the script at this point.

Task 3 (5 marks)

Write a script that counts the number of files and directories within a given directory according to their properties.

Requirements:

• Call the script  countdf.sh 
• When the script is run, the path to a directory will be used by your tutor at the command line, e.g.

./countdf.sh ~/CSI6203/backups/june2020. This is an example path only, so do not hard- code it into your script.

• The output of the script to the terminal will appear as follows:

The [dirname] directory contains:

x files that contain data

x files that are empty x non-empty directories x empty directories

where [dirname] represents the directory of your tutor’s choosing and x represents the number of files and directories found matching each criterion.

• Be sure that the script can be run from any directory it is placed in within your tutor's Linux user directory structure.
• There is no need for data validation in this script; your tutor will enter a full path/directory that does

exist and within which a range of files and directories also exist.