mountraw

#!/bin/bash

file=$1
part=$2
dest=$3

if [[ -z $part || -z $file || -z $dest ]];then
  echo "usage $0 file part dest"
  exit 1
fi
mkdir -p $dest
npart=$(fdisk -l $file | grep "^$file" | sed 's/*//g' | wc -l)
t=$(( $npart - $part + 1))
sector=$(fdisk -l $file | grep "^$file" | sed 's/*//g' | awk '{print $2}' | tail -$t | head -1)
offset=$(( $sector * 512 ))
mount -o loop,offset=$offset $file $dest

???