Gets macOS X Installer app version.

macOSInstaller_version.sh

#!/bin/sh

# Shamelessly stolen from https://loefflmann.blogspot.com.au/2015/03/finding-os-x-version-and-build-in-install-os-x-app.html
# Provide the path to the installer file from the command line.
if [[ ! -z $1 ]]; then
    os_installer_path="$1"

    echo "Attaching ${1}"
    hdiutil attach "${os_installer_path}/Contents/SharedSupport/InstallESD.dmg" -quiet -noverify -nobrowse -mountpoint /Volumes/InstallESD.$$
    hdiutil attach "/Volumes/InstallESD.$$/BaseSystem.dmg" -quiet -noverify -nobrowse -mountpoint /Volumes/BaseSystem.$$

    os_ver=$(defaults read "/Volumes/BaseSystem.$$/System/Library/CoreServices/SystemVersion.plist" ProductVersion)
    build=$(defaults read "/Volumes/BaseSystem.$$/System/Library/CoreServices/SystemVersion.plist" ProductBuildVersion)

    echo "OS Version: ${os_ver} (${build})"

    echo "Detaching ${1}"
    hdiutil detach "/Volumes/BaseSystem.$$" -quiet
    hdiutil detach "/Volumes/InstallESD.$$" -quiet
else
    echo "Please specify path to macOS Install application."
fi