Formatting numbers to fixed width

Question

I have this output:

30.1.2003
3.3.2003
25.12.2003

I want to make print each value except the year in two digits (might have leading values). i.e

30.01.2003
03.03.2003
25.12.2003

Answer 1

You can use printf:

echo 30.1.2003 | tr . ' ' | xargs printf '%02d.%02d.%04d\n'

Answer 2

awk -F. -v OFS="."  '{for(i=1;i<=NF;i++)$i=(length($i)<2?"0":"")$i}7' file

if your output was from some process, do :

yourApp|awk -F. -v OFS="."  '{for(i=1;i<=NF;i++)$i=(length($i)<2?"0":"")$i}7'