Miscalleneous Shell Scripts

A collection of bash shell scripts serving as the solution to the questions in this pdf file

Below, the scripts are listed in the order of the question they answer:

1. reading.sh
2. character-count.sh
3. logtime.sh
4. read-empty.sh
5. image-conversion.sh
6. ip-hosts.sh
7. mail-merge.sh

The follwing is a short discussion on a few of the questions that needed some supplemenatry information apart from the scripts themsevels and the comments therein:

2. character-count.sh

The required JUJAYetu.txt text file is in the current directory

4. read-empty.sh

You can test that this command behaves as expected using the ./fav-animals directory.

5. image-conversion.sh

This script depends on the imagemagik package. For Debain-based systems, the following command can be used to get it:

sudo apt update
sudo apt install imagemagik

You can test that this command behaves as expected using the images in ./images/bmps

Image Attributions

These are the attributions for the images in the images folder.

• The Red Train by HanzoAI
• pink-and-green-vintage-car-parked-beside-brown-concrete-building-during-daytime by hidde schalm

6. ip-hosts.sh

The functionality is implemented using the ping command. The same functionality can be achieved (much faster, by the way) using the fping command with the -a flag. However, unlike ping, fping does not come shipped with most Linux distributions. For Debian-based systems you can install it using the following commands:

sudo apt udpdate
sudo apt install net-tools

The fping implementation is more succint than the implementation given here.

7. mail-merge.sh

For this script to run, you need the jq package installed on your system. For Debian systems:

sudo apt update
sudo apt install jq

This package is a lightweight and flexible command line JSON processor, but here, it has been used to url-encode the message in order to make sure that special characters like \n and & are handled correctly.

The implementation also assumes that the x-www-browser alternative is set (preferrably to Firefox). It calls x-www-browser with a mailto url containing the subject, recepients and message.

An alternative to this can be to use the open command with the mailto url. This assumes that the default email application is set.

You can user the data in the ./mail-merge and the subject "Invitation to Innovation Incubation" to confirm it works as expected.

The script was tested with Firefox but did not work with Chrome. Chrome completely ignored the mailto url when trying to pass it through the terminal.