July 18, 2024

Reverse (flip) the order of rows of a text file with tac

Run:

$ tac input.txt > output.txt

and the content of the file input.txt:

2023-12-18T00:00:00+02:00   
2024-01-18T00:00:00+02:00
2024-01-18T00:00:00+02:00
2024-02-18T00:00:00+02:00
2024-03-18T00:00:00+02:00   
2024-03-18T00:00:00+02:00   
2024-04-18T00:00:00+02:00
2024-04-18T00:00:00+02:00   
2024-04-18T00:00:00+02:00   
2024-07-18T00:00:00+02:00
2024-07-17T00:00:00+02:00   

becomes:

2024-07-17T00:00:00+02:00   
2024-07-18T00:00:00+02:00
2024-04-18T00:00:00+02:00   
2024-04-18T00:00:00+02:00   
2024-04-18T00:00:00+02:00
2024-03-18T00:00:00+02:00   
2024-03-18T00:00:00+02:00   
2024-02-18T00:00:00+02:00
2024-01-18T00:00:00+02:00
2024-01-18T00:00:00+02:00
2023-12-18T00:00:00+02:00

in the file output.txt.

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