Bash grep from text file and edit - bash

Question

I am doing a update on the file test.txt which stores some info about storybooks
I've the code below for the function but i realise that using this method of grep, i am unable to get the rest of the values for price quantity and sold which are not mentioned in the grep command.
Is there a better command i can use for this case?
Thanks in advance for replies. :)
echo "Title: "
read title
echo ""
echo "Author: "
read author
echo ""
echo "Number of copies sold: "
read numSold
if grep -iq "$title:$author:" test.txt
then
echo "Current Book Info :"
echo "$title, $author, $price, $quantity, $sold"
echo ""
newQuantity=`expr $quantity - $numSold`
newSold=`expr $sold + $numSold`
sed -i "s/^\($title:$author:[^:]*\):[^:]*:/\1:$newQuantity:/" BookDB.txt
sed -i "s/^\($title:$author:.*\):.*$/\1:$newSold/" BookDB.txt
echo "New Book Info :"
echo "$title, $author, $price, $quantity, $sold"
fi

Answer 1

Well unfortunately the build of the test.txt is unknow.
If you could show an example that can help.
But if the Price quantity and other staff are in the 1-2 line away from the line you grepping you can use the grep -A 2 (which will grep 2 next lines) or -B 2 (2 lines from above)
after that u can just remove the '\n'from the results and print it :
grep -A 2 "$title:$author:*" | tr '\n' ' '
this will give you a line (build out of 3 lines) with all the data.
Of course its based on the how test.txt is build.
some thing like this :
> grep -A 2 "Konan Doil:Story" test.txt
Konan Doil:Story
Price - $$$$$
Quantity - XXXX, Sold - 99999
In response to the comment below :
I think its better then use array to save the input. after that u can do
with array what ever you want as the values are same
(Index 0 = Author, 1 = Book Name ... etc.)
>IFS=$':'; i=0 ; for line in $(grep "Konan Doil:Good" test.txt) ; do arr[$i]=$line; i=$(($i + 1)) ; done
>echo "${arr[0]}"
Konan Doil
>echo "${arr[1]}"
Good story
>echo "${arr[3]}"
XXXXX
>echo "${arr[4]}"
YYYYYY
>echo "${arr[2]}"
$$$$$
>