commandline session $ 4.1.5 1 270—> echo “fastest 1000 cars” | sed “s/1000/2000/” fastest 2000 cars $ 4.1.5 2 271—> echo “fastest 1000 cars” | sed “s/1*/2000/” 2000fastest 1000 cars $ 4.1.5 3 272—> $ 4.1.5 3 272—> echo “fastest 1000 cars” | sed “s/2*/2000/” 2000fastest 1000 cars $ 4.1.5 4 273—> echo “fastest 1000 …