Upgrade Calibre on Mac OS X to latest version

calibre-upgrade.sh

#!/bin/bash

CALIBRE_DOWN="http://status.calibre-ebook.com/dist/osx32"
CALIBRE_LAST=`curl --head --silent ${CALIBRE_DOWN} | grep "Location" \
	| awk '{print $2}' | perl -pi -e 's/\r\n//g'`

CURRENT_USER=`whoami`
CALIBRE_NAME=`echo ${CALIBRE_LAST} | awk -F '/' '{print $5}'`
CALIBRE_FILE="/Users/${CURRENT_USER}/Downloads/${CALIBRE_NAME}"

if [ ! -f $CALIBRE_FILE ]; then
	wget "${CALIBRE_LAST}" -O "${CALIBRE_FILE}"
fi

if [ -f $CALIBRE_FILE ]; then
	cd "/Applications/"
	rm -rf 'Calibre.app'

	CALIBRE_VOLUME=`hdiutil attach "${CALIBRE_FILE}" \
		| grep "calibre" | awk '{print $3}'`

	cp -R "${CALIBRE_VOLUME}/calibre.app" "/Applications/Calibre.app"

	hdiutil detach "${CALIBRE_VOLUME}" > /dev/null
fi