How does commnad tail implement ?
Thank you .

Captured from Man Page:


tail accepts two option formats: the new one, in which
numbers are arguments to the option letters, and the old
one, in which a `+' or `-' and optional number precede any
option letters.

If a number (`N') starts with a `+', tail begins printing
with the Nth item from the start of each file, instead of
from the end.

for more info you can check your man page. Might be diffrent from mine.