GIIA24

Shell scripting in bash

learn to write basic and useful script

Arithmetic with bash

As Bash supports integer artihmetics with the let command:

x=1+1
echo $x  # incorrect as it will print 1+1

let x=1+1
echo $x   #correct

Unfortunatly bash dones not natively support floating point arithmetic, hence we will rely on an external utilities called bc.

bc is actually it’s own complete language!.

We generally create an expression and pass it to bf through pipelines.

We include the -l option for floating point arithmetic

echo 1/2 | bc -l
.50000000

Using this command, write a script to ask the user for an integer N and print the following entities:

Now write a script to solve a second orde equation

$ ax^2 + bx + C $

Using Substritution

The goal for this questions is to create a :

using substitution.

  1. The string should be named BIRTHDATE and should contain the text Jan 1,2000.
  2. The integer should be named Presents and should contain the number 10.
  3. The complex variable should be named BIRTHDAY and should contain the full weekday name of the day matching the date in variable BIRTHDATE

For example Saturuday. Use the the date command to convert a date format into a different format.

Looping I

Write a script to print the odd numbes from 1 to 99.

1
3
5
.
.
.
99

Writing functions

In this exercise, you will need to write a function called ENGLISH_CALC which can process sentences such as:

and the print the result as: