Команда grep

echo -e "F372EB96\nF372EB9\nF372EB\n" |
while read line; do
  echo $line | grep -Po '..?' |
  while read i; do
    echo -en "$i "
  done
  echo ""
done

echo -e "F372EB96\nF372EB9\nF372EB" |
while read line; do
  a=( $(echo $line | grep -Po '..?') )
  echo "/${a[0]}/"$(echo "ibase=16; ${a[1]}" | bc)"/${a[2]}/${a[3]}"
done

$ echo -e "F372EB96\nF372EB9\nF372EB" | \
> sed -e 's,..,&/,g' -e 's,[^/]$,&/,'
F3/72/EB/96/
F3/72/EB/9/
F3/72/EB/

echo -e "F372EB96\nF372EB9\nF372EB" |
while read line; do
  a=$(echo "ibase=16; ${line:0:2}" | bc)
  b=$(echo "ibase=16; ${line:2:2}" | bc)
  c=$(echo "ibase=16; ${line:4:2}" | bc)
  d=$(echo "ibase=16; ${line:6:2}" | bc)
  echo "/$a/$b/$c/$d"
done

echo -e "F372EB96\nF372EB9\nF372EB" |
while read line; do
  a=( $(echo "ibase=16; "\
    "$(echo $line |
       sed 's/../&; /g' |
       sed 's/; $//')" | bc ) )
  for i in ${a[@]}; do
    echo -en "/$i"
  done
  echo ""
done