Learning Linux Shell Scripting - Second Edition

Holding and exchanging – the h and x commands

This is an exchange command. By using this command, we can exchange the holding buffer with the current line in the pattern buffer.

Here is an example:

    $ sed -e '/Apple/h'  -e '/Cashew/x' 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
    Apple      2       3            6
  

In this example, the line with the Apple pattern is stored in the holding buffer. When the pattern with Cashew is found, that line will be exchanged with the holding buffer.