#!/bin/bash
STR="Its a small world afterall"
CNT=$(wc -c <<< $STR})
TMP_CNT=0

printf "Char Hex\n"

while [ ${TMP_CNT} -lt $[${CNT} -1] ]; do
  printf "%-5s 0x%-2X\n" "${STR:$TMP_CNT:1}" "'${STR:$TMP_CNT:1}"
  TMP_CNT=$[$TMP_CNT+1]
done

Char Hex
I     0x49
t     0x74
s     0x73
      0x20
a     0x61
      0x20
s     0x73
m     0x6D
a     0x61
l     0x6C
l     0x6C
      0x20
w     0x77
o     0x6F
r     0x72
l     0x6C
d     0x64
      0x20
a     0x61
f     0x66
t     0x74
e     0x65
r     0x72
a     0x61
l     0x6C
l     0x6C
      0x0