|How about you read each line and store it in an array of lines.
As you read each line, shuffle the existing lines through the array and read in the current line.
That way you will always have the last 4 lines in your array.
When you reach the end, just display the contents of your line array.
Be aware that your file may not have 8+ lines. It might have only 2 or it might have six (resulting in the two middle lines being printed twice).
You will have to check for this.
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