Question

I have a problem.
I must represent each number with exactly 2 digits (i.e. 0F instead of F)

my code looks something like that:
1. read number of ascii chars are in an environment variable (using wc -w)
2. converting this number to hexadecimal (using bc).

How can I make sure the number I’ll get after stage 2 will include a leading 0 (if necessary)

Thanks,
Amigal

Answer 1

Run it through printf:

$ printf "%02s" 0xf
0f

If you have the digits of the number only in a variable, say $NUMBER, you can concatenate it with the required 0x prefix directly:

$ NUMBER=fea
$ printf "%04x" 0x$NUMBER
0fea