tail

tail is a simple utility that displays the last n lines of a file, or input. By default, it prints the last 10 lines. To control the number of lines printed, use the -n flag.

tail myfile.txt
Output
line91
line92
line93
line94
line95
line96
line97
line98
line99
line100
tail -n 3 myfile.txt
Output
line98
line99
line100