Bash: print leading zeros for numbers in a for loop

• for ((i=1; i>=100; i++)); do
      echo $(printf "%03d" $i)
  done

• BASH 4+

  for i in {001..100}; do
      echo "$i"
  done

  create 100 100k files:

  for i in {001..100}; do dd if=/dev/urandom of=100K_${i}.dat  bs=1024  count=100; done