distro sh function

distro.sh

# distro prints the detected operating system including linux distros.
# Also parses ID_LIKE for common distro bases.
#
# Example outputs:
# - macos -> macos
# - freebsd -> freebsd
# - ubuntu, raspbian, debian ... -> debian
# - amzn, centos, rhel, fedora, ... -> fedora
# - opensuse-{leap,tumbleweed} -> opensuse
# - alpine -> alpine
# - arch -> arch
#
# Inspired by https://github.com/docker/docker-install/blob/26ff363bcf3b3f5a00498ac43694bf1c7d9ce16c/install.sh#L111-L120.
distro() {
  if [ "$OS" = "macos" ] || [ "$OS" = "freebsd" ]; then
    echo "$OS"
    return
  fi

  if [ -f /etc/os-release ]; then
    (
      . /etc/os-release
      if [ "${ID_LIKE-}" ]; then
        for id_like in $ID_LIKE; do
          case "$id_like" in debian | fedora | opensuse)
            echo "$id_like"
            return
            ;;
          esac
        done
      fi

      echo "$ID"
    )
    return
  fi
}

# os_name prints a pretty human readable name for the OS/Distro.
distro_name() {
  if [ "$(uname)" = "Darwin" ]; then
    echo "macOS v$(sw_vers -productVersion)"
    return
  fi

  if [ -f /etc/os-release ]; then
    (
      . /etc/os-release
      echo "$PRETTY_NAME"
    )
    return
  fi

  # Prints something like: Linux 4.19.0-9-amd64
  uname -sr
}

arch() {
  case "$(uname -m)" in
  aarch64)
    echo arm64
    ;;
  x86_64)
    echo amd64
    ;;
  amd64) # FreeBSD.
    echo amd64
    ;;
  esac
}