Extract the NVIDIA Jetson L4T <RELEASE>.<MAJOR> version from /etc/nv_tegra_release

l4t-version.sh

function get_L4T_major_version_only {
  # Will return the L4T <release>.<major> version (ex: "32.6" or "32.4")
  local RELEASE=$(cat /etc/nv_tegra_release | grep -oP "R\d{2}" | grep -oP "\d{2}")
  local MAJOR_VERSION=$(cat /etc/nv_tegra_release | grep -oP "REVISION: \d{1}\.\d{1}" | grep -oP "\d{1}.\d{1}" | grep -oP "\d{1}". | grep -oP "\d{1}")
  echo "${RELEASE}.${MAJOR_VERSION}"
}