Shell Programming and Scripting

Google:Harry:45.00:50:100

echo "Please enter Title"
    read BookTitle
    echo "Please enter Author"
    read Author
    echo "Price"
    read Price
    echo "Quantity"
    read Quantity
    echo "Sold"
    read Sold
    echo "$BookTitle:$Author:$Price:$Quantity:$Sold" >> library.txt
    echo " Book Added Successfully!"

Book already exists

Please enter valid Title/Author

#!/bin/bash
echo "Please enter Title"
read BookTitle
echo "Please enter Author"
read Author
if [[ $(grep "^$BookTitle:$Author" library.txt | wc -l) -gt 0 ]]
then echo "Book already exists"
else 
    echo "Price"
    read Price
    echo "Quantity"
    read Quantity
    echo "Sold"
    read Sold
    echo "$BookTitle:$Author:$Price:$Quantity:$Sold" >> library.txt
    echo " Book Added Successfully!"
fi

case "$Author$BookTitle" in
    *[0-9,\!@#$%\(\)]*)  echo "Please enter a valid Title/Author" ;;
esac