Question

Write a short SAD program into a file and name the file according to our standard convention but with .sad extension, hence name it Lab_12_InitialName.sed.

You program should perform following operations on a file that I will use to test it:

1) Substitute all instances of cst 3523 with CST-3523

2) Remove all empty lines from the file

3) Insert your name before the first line of the file

4) Add the line stating your name as the last line of the file

Answer 1

I am assuming you wanted to write SED. Following will be the four commands to do the required operations. I will explain them after writing them.

1. #!/bin/bash
2. sed -i 's/cst 3523/CST-3523/g' "$1"
3. sed -i '/^$/d' "$1"
4. sed -i $'1i\\\n<your name>\n' "$1"
5. sed -i $'$a\\\n<your name>\n' "$1"

Here, replace <your name> with your name.

First line is just to identify which command to run when you make the file executable.

Second line replaces all instances of "cst 3523" with "CST-3523".

Third line removes all the empty lines.

Fourth and fifth are for adding your name.

We use "-i" option to change the file in-place. "$1" is the first argument, which will be the file you need to change when you run this script.