Address Book using shell Script

addessBook.sh

#!/usr/bin/env sh

# Program to implement an address book with options given below
#1. create the database
#2. View address book
#3. Insert a Record
#4. Delete a Record
#5. Modify the Record
#6. Exit

create () {
	touch address.txt
	echo "address database created"
}

insert () {
	if [[ "$1" == "" ]]; then
		echo "Enter the name"
		read name
	else
		name=$1
	fi
	if [[ "$(grep -i -c $name address.txt)" == 0 ]]; then
		echo "Enter the Address"
		read address
		echo "Enter the Mobile No"
		read number
		echo "Enter the Email Id"
		read emailId

		echo "$name $address $number $emailId" >> address.txt

		echo "Data Inserted Succesfully"
	else
		echo "Record for ${name} already exist"
	fi
}


view () {
	echo "Enter the name of the person to view a single entry or enter all to view the Database"
	read input
	if [[ "${input,,}" == "all" ]]; then
	  echo "============================================================================================================="
		cat address.txt
		echo "============================================================================================================="
	else
	  echo "============================================================================================================="
		echo "$(grep -i -c $input test.txt) records found"
		echo "--------------------------------------------------------------------------------------------------------------"
		grep -i $input address.txt
		echo "============================================================================================================="

	fi
}


modify () {
	echo "enter the name of the person whom record you want to edit"
	read name
	grep -i -v $name address.txt >> address1.txt
	cp address1.txt address.txt
	rm address1.txt
	insert $name
}


delete () {
	echo "Are you sure you want to delete the database: Press Y[Yes]/N[No]"
	read confirmation

	if [[ "${confirmation,,}" == "y" || "${confirmation,,}" == "yes" ]]; then
		rm address.txt
		echo "Database Deleted"

	elif [[ "${confirmation,,}" == "no" || "${confirmation,,}" == "n" ]]; then
		return
	else
		echo "Invalid Option"
	fi
}


while :
 do
	echo "enter your choice"
	echo " 1->create"
	echo " 2->insert"
	echo " 3->view"
	echo " 4->modify"
	echo " 5->delete"
	echo " 6->exit"
	read ch

	case $ch in
	1)create ;;
	2)insert ;;
	3)view ;;
	4)modify ;;
	5)delete ;;
	6)exit 0;;
	esac
done