Downloads the latest Google Chrome DMG file and installs it on a Mac

update-chrome.sh

#!/bin/sh

dmgfile="googlechrome.dmg"
volname="Google Chrome"
logfile="/Library/Logs/GoogleChromeInstallScript.log"

url='https://dl.google.com/chrome/mac/stable/GGRO/googlechrome.dmg'


/bin/echo "--" >> ${logfile}
/bin/echo "`date`: Downloading latest version." >> ${logfile}
/usr/bin/curl -s -o /tmp/${dmgfile} ${url}
/bin/echo "`date`: Mounting installer disk image." >> ${logfile}
/usr/bin/hdiutil attach /tmp/${dmgfile} -nobrowse -quiet
/bin/echo "`date`: Installing..." >> ${logfile}
ditto -rsrc "/Volumes/${volname}/Google Chrome.app" "/Applications/Google Chrome.app"
/bin/sleep 10
/bin/echo "`date`: Unmounting installer disk image." >> ${logfile}
/usr/bin/hdiutil detach $(/bin/df | /usr/bin/grep "${volname}" | awk '{print $1}') -quiet
/bin/sleep 10
/bin/echo "`date`: Deleting disk image." >> ${logfile}
/bin/rm /tmp/"${dmgfile}"

exit 0

trying to install