Uses hdiutil to create a raw disk image with .img extension

rawdisk.sh

#!/usr/bin/env bash

if [ "$1" = "-h" -o "$1" = "--help" -o -z "$1" ]; then cat <<EOF
Usage:
  `basename $0` <diskimage>

Converts a Disk Image (DMG, ISO) to raw format.
EOF
exit; fi

hdiutil convert -format UDTO $1 -o $1
if [ -f "$1.cdr" ]; then
	IMAGE="$(echo $1.cdr | sed -E 's/(\..{0,3})?\.cdr$/.img/')"
	mv "$1.cdr" $IMAGE
	echo
	echo Raw Image: $IMAGE
fi