Padding zeros in a string

Question

I\'m writing a bash script to get some podcasts. The problem is that some of the podcast numbers are one digits while others are two/three digits, therefore I need to pad t

Answer 1

This is in response to an answer given by cC Xx. It will work only until a's value less is than 5 digits.

Consider when a=12345678. It'll truncate the leading digits:

a="12345678" 
b="00000${a}" 
c="${b: -5}" 
echo "$a, $b, $c"

This gives the following output:

12345678, 0000012345678, 45678

Putting an if to check value of a is less than 5 digits and then doing it could be solution:

if [[ $a -lt 9999 ]] ; then b="00000${a}" ; c="${b: -5}" ;  else c=$a; fi