touch file.txt
echo Linia0 > file.txt
echo Linia1 >> file.txt
echo Linia2 >> file.txt
echo Linia3 >> file.txt

cat file.txt
tac file.txt
more file.txt //enter 1-linia, spacja-cala srona
less file.txt
head file.txt -n 1
tail file.txt -n 1