Description

In the following example, we want to 'move' all the lines containing 'this' to the end of a file, i.e., display lines not containing 'this' first.

Raw Input		Desired Output
1 this 2 this 3 another 4 another 5 this 6 another 7 this 8 another 9 this		3 another 4 another 6 another 8 another 1 this 2 this 5 this 7 this 9 this

Script and Comments

Script₁

[ 1] /this/H
[ 2] /this/!p
[ 3] $!d
[ 4] x
[ 5] s/^\n//
[ 6] /^$/d

Comments

If a line contains 'this', Step [1] will copy it to the Hold Space; otherwise Step [2] will print it.
Then, if the current line is not the last line of a file, Step [3] will delete it and start next cycle.
After processing the last line (copy it to the Hold Space or not),
- Step [4] will exchange the contents of the Pattern Space and the Hold Space. Then the PS will have those lines containing 'this'.
- Step [5] will remove the leading new line character.
- If the PS is empty, which implies that the file does not have any line containing 'this', without the help of Step [6], you will get a trailing empty line.