pvdd.sh

#!/bin/bash

if [[ $EUID -ne 0 ]]; then
  echo "ERROR: Must be run with sudo" >&2
  exit 1
fi

if [[ -z "$1" || ! -f "$1" ]]; then
  echo "USAGE: $0 <disk_image_file>" >&2
  exit 1
fi

IF=$1

disk_list=$(diskutil list external physical | grep 0:)
num_of_disks=$(echo "$disk_list" | wc -l)

echo "------------------------------------------------------------------------------"
echo "   \#:                       TYPE NAME                    SIZE       IDENTIFIER"
echo "$disk_list"
echo "------------------------------------------------------------------------------"

if [ $num_of_disks -eq 1 ]; then
    disk_identifier=$(echo "$disk_list" | awk '{print $NF}')
else
    if [ $num_of_disks -eq 0 ]; then
        echo "External disk not found"
        exit 1
    else
        read -p "Choose a Disk: /dev/disk" disk_number
        disk_identifier="disk$disk_number"
    fi
fi

OF="/dev/$disk_identifier"

echo "Unmounting $OF..."
diskutil unmountDisk $OF

echo "writing $IF to $OF"
pv $IF | dd of=$OF bs=4M

sync

echo "Finished writing, unmounting $OF..."
diskutil unmountDisk $OF

echo "Done."