MergeDMG

#!/bin/bash

# usage: MergeDMG <tmpdir> <template> <output> <source files dirs...>

set -avxe

DMG_SCRATCH_DIR="$1"
DMG_TEMPLATE="$2"
DMG_OUTPUT="$3"
shift; shift; shift;

if [ ! -d "$DMG_SCRATCH_DIR" ]; then
	echo "error: $DMG_SCRATCH_DIR does not exist" >&2
	exit 1
fi

if [ ! -e "$DMG_TEMPLATE" ]; then
	echo "$DMG_TEMPLATE does not exist" >&2
	exit 1
fi	

if [ -e "$DMG_OUTPUT".tmp.dmg ]; then
	rm "$DMG_OUTPUT".tmp.dmg || exit 1
fi

DMG_MOUNT_POINT="$TMPDIR"/MountPoint."$$"

if [ -d "$DMG_MOUNT_POINT" ]; then
	rmdir "$DMG_MOUNT_POINT" || exit 1
fi
mkdir "$DMG_MOUNT_POINT" || exit 1

if [ -e "$DMG_SCRATCH_DIR"/DMGShadow ]; then
	rm "$DMG_SCRATCH_DIR"/DMGShadow || exit 1
fi

hdiutil attach "$DMG_TEMPLATE" \
	-readwrite \
	-shadow "$DMG_SCRATCH_DIR"/DMGShadow \
	-mountpoint "$DMG_MOUNT_POINT" \
	-nobrowse \
	|| exit 1

for ITEM in "$DMG_MOUNT_POINT"/*; do
	COPIED=NO
	for SOURCE in "$@"; do
		if [ "$COPIED" == "NO" ]; then
			ITEM_BASENAME="`basename "$ITEM"`"
			if [ -d "$SOURCE"/"$ITEM_BASENAME" ]; then
				rsync -avE --exclude="*/.svn" "$SOURCE"/"$ITEM_BASENAME" "$DMG_MOUNT_POINT"
				COPIED=YES
			elif [ -f "$SOURCE"/"$ITEM_BASENAME" ]; then
				cp -fv "$SOURCE"/"$ITEM_BASENAME" "$DMG_MOUNT_POINT"/"$ITEM_BASENAME"
				COPIED=YES
			fi
		fi
	done
	
	if [ "$COPIED" == "NO" ]; then
		echo "error: Found no appropriate correspondence for $ITEM in the source folders." >&2
		exit 1
	fi
done

sync

hdiutil eject "$DMG_MOUNT_POINT" || exit 1
rmdir "$DMG_MOUNT_POINT" || exit 1

hdiutil convert "$DMG_TEMPLATE" \
	-o "$DMG_OUTPUT".tmp.dmg \
	-format UDZO \
	-imagekey zlib-level=9 \
	-shadow "$DMG_SCRATCH_DIR"/DMGShadow \
	|| exit 1

mv "$DMG_OUTPUT".tmp.dmg "$DMG_OUTPUT" || exit 1