How to format a number in bash, possibly with printf?

Question

This so simple script is failing :

#!/bin/bash
n=1
printf -v fn \"%05d\" $n
echo $fn

with

3: printf: Illegal option -v
         


        

Answer 1

As other answers tell you that older BASH version versions don't support printf -v but here is what you can do that in older BASH to set fn:

#!/bin/bash
n=1
fn=$(printf "%05d" "$n")
echo "$fn"