$cat u.txt UPPERCASE $cat l.txt cat: l.txt: No such file or directory $tr A-Z a-z l.txt $cat u.txt UPPERCASE $cat l.txt uppercase $
BEAUTY AND PLAY
$cat u.txt UPPERCASE $cat l.txt cat: l.txt: No such file or directory $tr A-Z a-z l.txt $cat u.txt UPPERCASE $cat l.txt uppercase $