How to use Arrays in Shell scripts

We know what an array is. An array is a variable which can store multiple values in the same name. These values can be accessed by using the subscripts. The whole of the array can be accessed by just mentioning the array name without any subscripts. Let us see some of the important operations using array in BASH with the help of the below script.

#!/bin/sh # the name of this script is array.sh array=(ram rick sittik rahim) # assigning values to the array len=${#array[*]} # Number of elements of the array echo "The array contains $len members. They are:" i=0 # Displaying the members of the array while [ $i -lt $len ]; do echo "$i: ${array[$i]}" let i++ done #Some of the operations echo "Adding "bill" to the end of the array" array=( "${array[@]}" "bill" ) echo "Listing all the elements in the array" echo "${array[@]}" echo "Listng all the elements in the array" # This is another way echo "${array[*]}" echo "Deleting \"rick\"" unset array[1] # Same as array[1]="" echo "Now the array is" echo "${array[@]}" echo "length of 3rd element in the array" len1=${#array[2]} echo $len echo "Deleting the whole array" unset array echo "${array[@]}" # The array is empty


The output of the above script would be

$ ./array.sh
The array contains 4 members. They are:
0: ram
1: rick
2: sittik
3: rahim
Adding bill to the end of the array
Listing all the elements in the array
ram rick sittik rahim bill
Listing all the elements in the array
ram rick sittik rahim bill
Deleting "rick"
Now the array is
ram sittik rahim bill
length of 3rd element in the array
6
Deleting the whole array