"cat" only some lines?

Question

Is it possible to cat only selected lines of a file? For example the first 10, last 15, or "from 20 to 30"?

Answer 1

That's what the head and tail programs are for :)

First ten lines

head -n 10 FILE

Last ten lines

tail -n 10 FILE

From lines 3 to 5:

head -n 5 FILE | tail -n 3