Удаление строк bash
cat /etc/apt/sources.list | grep "^[^#*/;]" > /etc/apt/sources.list.save
или
egrep -v '^#|^$' /etc/apt/sources.list > /etc/apt/sources.list.save
cat /etc/apt/sources.list | grep "^[^#*/;]" > /etc/apt/sources.list.save
или
egrep -v '^#|^$' /etc/apt/sources.list > /etc/apt/sources.list.save