os=$(uname -s)
PLATFORM_SED="sed -i ''"

# choose correct version of sed utility for platform
case "$os" in
    Linux*)
        # GNU utilities
        PLATFORM_SED="sed -i"
        ;;
    Darwin*)
        # BSD utilities (macOS)
        PLATFORM_SED="sed -i ''"
        ;;
    *BSD*)
        # Other BSD variants (FreeBSD, OpenBSD, etc)
        PLATFORM_SED="sed -i ''"
        ;;
    *)
        echo "Unknown operating system: $os"
        exit 1
        ;;
esac