We have already seen that sed has a pattern buffer. sed has one more type of buffer called a holding buffer. With the h command, we can inform sed to store the pattern buffer in the holding buffer. Whenever we need the line that is stored in the pattern buffer, we can get it with the g command, that is, get the buffer.
Here is an example:
$ sed -e '/Product/h' -e '$g' shopping.txt
The output is as follows:
Product Quantity Unit_Price Total_Cost Apple 2 3 6 Orange 2 .8 1.6 Papaya 2 1.5 3 Chicken 3 5 15 Cashew 1 10 10 Product Quantity Unit_Price Total_Cost
In this example, the line containing the Product pattern is stored in the holding buffer by the h command. Then, the next editing command asks ...