diff --git a/.gitignore b/.gitignore
index ec58ed7..5eed003 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
-.*/
-_*/
-bin/
-node_modules/
+.*/
+_*/
+bin/
+node_modules/
+*.zip
+push.sh
diff --git a/LICENSE.md b/LICENSE.md
index c89b4c5..e421583 100644
--- a/LICENSE.md
+++ b/LICENSE.md
@@ -1,5 +1,27 @@
-Google/Blockly is licensed under Apache License (Version 2.0).
-
-Microsoft/pxt-blockly is licensed under MIT.
-
-ocoge is licensed under MIT.
+Google/Blockly is licensed under Apache License (Version 2.0).
+
+Microsoft/pxt-blockly is licensed under MIT.
+
+ocoge is licensed under MIT.
+
+MIT License
+
+Copyright (c) 2021 ocoge club, Ueno Gakushujuku
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
\ No newline at end of file
diff --git a/README.md b/README.md
index 06d7ae0..b4bd8c8 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,10 @@
-# ocoge
-"大岩産 Code Generator" は、Google Blockly ライブラリを使用した、Raspberry Pi 上で動作するブロックプログラム開発・実行環境です。
\ No newline at end of file
+# ocoge
+"大岩産 Code Generator" は、Google Blockly ライブラリを使用した、Raspberry Pi 上で動作するブロックプログラム開発・実行環境です。
+
+### 免責
+このアプリケーションは特定の環境下で使用する目的で、専門知識を持たない日曜プログラマによって無計画に開発されています。アドバイス・ご意見・ご要望は有難く承りますが、対応の保証はいたしかねます。
+また、このアプリケーションを使用したことによるいかなる損害に関しても当方は一切の責任を負わないものとします。
+
+### Disclaimer
+This application has been unplannedly developed by a non-expert amateur programmer for use in specific environments. We appreciate your advice, opinions, and requests, but we cannot guarantee the response.
+We do not take any responsibility for any damage caused by using this application.
\ No newline at end of file
diff --git a/installer/files/n b/installer/files/n
new file mode 100644
index 0000000..f7db50b
--- /dev/null
+++ b/installer/files/n
@@ -0,0 +1,1485 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC2155
+# Disabled "Declare and assign separately to avoid masking return values": https://github.com/koalaman/shellcheck/wiki/SC2155
+
+#
+# Log <type> <msg>
+#
+
+log() {
+  printf "  ${SGR_CYAN}%10s${SGR_RESET} : ${SGR_FAINT}%s${SGR_RESET}\n" "$1" "$2"
+}
+trace_log() {
+  >&2 log "$1" "$2"
+}
+
+#
+# Exit with the given <msg ...>
+#
+
+abort() {
+  >&2 printf "\n  ${SGR_RED}Error: %s${SGR_RESET}\n\n" "$*" && exit 1
+}
+
+#
+# Synopsis: trace message ...
+# Debugging output to stderr, not used in production code.
+#
+
+function trace() {
+  >&2 printf "trace: %s\n" "$*"
+}
+
+#
+# Synopsis: echo_red message ...
+# Highlight message in colour (on stdout).
+#
+
+function echo_red() {
+  printf "${SGR_RED}%s${SGR_RESET}\n" "$*"
+}
+
+#
+# Synopsis: n_grep <args...>
+# grep wrapper to ensure consistent grep options and circumvent aliases.
+#
+
+function n_grep() {
+  GREP_OPTIONS='' command grep "$@"
+}
+
+#
+# Setup and state
+#
+
+VERSION="7.0.1"
+
+N_PREFIX="${N_PREFIX-/usr/local}"
+N_PREFIX=${N_PREFIX%/}
+readonly N_PREFIX
+readonly CACHE_DIR=$N_PREFIX/n/versions
+
+N_NODE_MIRROR=${N_NODE_MIRROR:-${NODE_MIRROR:-https://nodejs.org/dist}}
+N_NODE_MIRROR=${N_NODE_MIRROR%/}
+readonly N_NODE_MIRROR
+
+N_NODE_DOWNLOAD_MIRROR=${N_NODE_DOWNLOAD_MIRROR:-https://nodejs.org/download}
+N_NODE_DOWNLOAD_MIRROR=${N_NODE_DOWNLOAD_MIRROR%/}
+readonly N_NODE_DOWNLOAD_MIRROR
+
+# Using xz instead of gzip is enabled by default, if xz compatibility checks pass.
+# User may set N_USE_XZ to 0 to disable, or set to anything else to enable.
+# May also be overridden by command line flags.
+
+# Normalise external values to true/false
+if [[ "${N_USE_XZ}" = "0" ]]; then
+  N_USE_XZ="false"
+elif [[ -n "${N_USE_XZ+defined}" ]]; then
+  N_USE_XZ="true"
+fi
+# Not setting to readonly. Overriden by CLI flags, and update_xz_settings_for_version.
+
+N_MAX_REMOTE_MATCHES=${N_MAX_REMOTE_MATCHES:-20}
+# modified by update_mirror_settings_for_version
+g_mirror_url=${N_NODE_MIRROR}
+g_mirror_folder_name="node"
+
+# Options for curl and wget.
+# Defining commands in variables is fraught (https://mywiki.wooledge.org/BashFAQ/050)
+# but we can follow the simple case and store arguments in an array.
+
+GET_SHOWS_PROGRESS="false"
+# --location to follow redirects
+# --fail to avoid happily downloading error page from web server for 404 et al
+# --show-error to show why failed (on stderr)
+CURL_OPTIONS=( "--location" "--fail" "--show-error" )
+if [[ -t 1 ]]; then
+  CURL_OPTIONS+=( "--progress-bar" )
+  command -v curl &> /dev/null && GET_SHOWS_PROGRESS="true"
+else
+  CURL_OPTIONS+=( "--silent" )
+fi
+WGET_OPTIONS=( "-q" "-O-" )
+
+# Legacy support using unprefixed env. No longer documented in README.
+if [ -n "$HTTP_USER" ];then
+  if [ -z "$HTTP_PASSWORD" ]; then
+    abort "Must specify HTTP_PASSWORD when supplying HTTP_USER"
+  fi
+  CURL_OPTIONS+=("-u $HTTP_USER:$HTTP_PASSWORD")
+  WGET_OPTIONS+=("--http-password=$HTTP_PASSWORD"
+                "--http-user=$HTTP_USER")
+elif [ -n "$HTTP_PASSWORD" ]; then
+  abort "Must specify HTTP_USER when supplying HTTP_PASSWORD"
+fi
+
+# Set by set_active_node
+g_active_node=
+
+ACTIVATE=true
+ARCH=
+
+# ANSI escape codes
+# https://en.wikipedia.org/wiki/ANSI_escape_code
+# https://no-color.org
+# https://bixense.com/clicolors
+
+USE_COLOR="true"
+if [[ -n "${CLICOLOR_FORCE+defined}" && "${CLICOLOR_FORCE}" != "0" ]]; then
+  USE_COLOR="true"
+elif [[ -n "${NO_COLOR+defined}" || "${CLICOLOR}" = "0" || ! -t 1 ]]; then
+  USE_COLOR="false"
+fi
+readonly USE_COLOR
+# Select Graphic Rendition codes
+if [[ "${USE_COLOR}" = "true" ]]; then
+  # KISS and use codes rather than tput, avoid dealing with missing tput or TERM.
+  readonly SGR_RESET="\033[0m"
+  readonly SGR_FAINT="\033[2m"
+  readonly SGR_RED="\033[31m"
+  readonly SGR_CYAN="\033[36m"
+else
+  readonly SGR_RESET=
+  readonly SGR_FAINT=
+  readonly SGR_RED=
+  readonly SGR_CYAN=
+fi
+
+#
+# set_arch <arch> to override $(uname -a)
+#
+
+set_arch() {
+  if test -n "$1"; then
+    ARCH="$1"
+  else
+    abort "missing -a|--arch value"
+  fi
+}
+
+#
+# Synopsis: set_insecure
+# Globals modified:
+# - CURL_OPTIONS
+# - WGET_OPTIONS
+#
+
+function set_insecure() {
+  CURL_OPTIONS+=( "--insecure" )
+  WGET_OPTIONS+=( "--no-check-certificate" )
+}
+
+#
+# Synopsis: update_mirror_settings_for_version version
+# e.g. <nightly/latest> means using download mirror and folder is nightly
+# Globals modified:
+# - g_mirror_url
+# - g_mirror_folder_name
+#
+
+function update_mirror_settings_for_version() {
+  if is_download_folder "$1" ; then
+    g_mirror_folder_name="$1"
+    g_mirror_url="${N_NODE_DOWNLOAD_MIRROR}/${g_mirror_folder_name}"
+  elif is_download_version "$1"; then
+    [[ "$1" =~ ^([^/]+)/(.*) ]]
+    local remote_folder="${BASH_REMATCH[1]}"
+    g_mirror_folder_name="${remote_folder}"
+    g_mirror_url="${N_NODE_DOWNLOAD_MIRROR}/${g_mirror_folder_name}"
+  fi
+}
+
+#
+# Synopsis: update_xz_settings_for_version version
+# Globals modified:
+# - N_USE_XZ
+#
+
+function update_xz_settings_for_version() {
+  # tarballs in xz format were available in later version of iojs, but KISS and only use xz from v4.
+  if [[ "${N_USE_XZ}" = "true" ]]; then
+    local resolved_major_version
+    resolved_major_version="$(echo "${1#v}" | cut -d '.' -f '1')"
+    if [[ "${resolved_major_version}" -lt 4 ]]; then
+      N_USE_XZ="false"
+    fi
+  fi
+}
+
+#
+# Synopsis: is_lts_codename version
+#
+
+function is_lts_codename() {
+  # https://github.com/nodejs/Release/blob/master/CODENAMES.md
+  # e.g. argon, Boron
+  [[ "$1" =~ ^([Aa]rgon|[Bb]oron|[Cc]arbon|[Dd]ubnium|[Ee]rbium|[Ff]ermium|[Gg]allium|[Hh]ydrogen|[Ii]ron)$ ]]
+}
+
+#
+# Synopsis: is_download_folder version
+#
+
+function is_download_folder() {
+  # e.g. nightly
+  [[ "$1" =~ ^(next-nightly|nightly|rc|release|test|v8-canary)$ ]]
+}
+
+#
+# Synopsis: is_download_version version
+#
+
+function is_download_version() {
+  # e.g. nightly/, nightly/latest, nightly/v11
+  if [[ "$1" =~ ^([^/]+)/(.*) ]]; then
+    local remote_folder="${BASH_REMATCH[1]}"
+    is_download_folder "${remote_folder}"
+    return
+  fi
+  return 2
+}
+
+#
+# Synopsis: is_numeric_version version
+#
+
+function is_numeric_version() {
+  # e.g. 6, v7.1, 8.11.3
+  [[ "$1" =~ ^[v]{0,1}[0-9]+(\.[0-9]+){0,2}$ ]]
+}
+
+#
+# Synopsis: is_exact_numeric_version version
+#
+
+function is_exact_numeric_version() {
+  # e.g. 6, v7.1, 8.11.3
+  [[ "$1" =~ ^[v]{0,1}[0-9]+\.[0-9]+\.[0-9]+$ ]]
+}
+
+#
+# Synopsis: is_node_support_version version
+# Reference: https://github.com/nodejs/package-maintenance/issues/236#issue-474783582
+#
+
+function is_node_support_version() {
+  [[ "$1" =~ ^(active|lts_active|lts_latest|lts|current|supported)$ ]]
+}
+
+#
+# Synopsis: display_latest_node_support_alias version
+# Map aliases onto existing n aliases, current and lts
+#
+
+function display_latest_node_support_alias() {
+  case "$1" in
+    "active") printf "current" ;;
+    "lts_active") printf "lts" ;;
+    "lts_latest") printf "lts" ;;
+    "lts") printf "lts" ;;
+    "current") printf "current" ;;
+    "supported") printf "current" ;;
+    *) printf "unexpected-version"
+  esac
+}
+
+#
+# Functions used when showing versions installed
+#
+
+enter_fullscreen() {
+  # Set cursor to be invisible
+  tput civis 2> /dev/null
+  # Save screen contents
+  tput smcup 2> /dev/null
+  stty -echo
+}
+
+leave_fullscreen() {
+  # Set cursor to normal
+  tput cnorm 2> /dev/null
+  # Restore screen contentsq
+  tput rmcup 2> /dev/null
+  stty echo
+}
+
+handle_sigint() {
+  leave_fullscreen
+  S="$?"
+  kill 0
+  exit $S
+}
+
+handle_sigtstp() {
+  leave_fullscreen
+  kill -s SIGSTOP $$
+}
+
+#
+# Output usage information.
+#
+
+display_help() {
+  cat <<-EOF
+
+Usage: n [options] [COMMAND] [args]
+
+Commands:
+
+  n                              Display downloaded node versions and install selection
+  n latest                       Install the latest node release (downloading if necessary)
+  n lts                          Install the latest LTS node release (downloading if necessary)
+  n <version>                    Install node <version> (downloading if necessary)
+  n run <version> [args ...]     Execute downloaded node <version> with [args ...]
+  n which <version>              Output path for downloaded node <version>
+  n exec <vers> <cmd> [args...]  Execute command with modified PATH, so downloaded node <version> and npm first
+  n rm <version ...>             Remove the given downloaded version(s)
+  n prune                        Remove all downloaded versions except the installed version
+  n --latest                     Output the latest node version available
+  n --lts                        Output the latest LTS node version available
+  n ls                           Output downloaded versions
+  n ls-remote [version]          Output matching versions available for download
+  n uninstall                    Remove the installed node and npm
+
+Options:
+
+  -V, --version         Output version of n
+  -h, --help            Display help information
+  -p, --preserve        Preserve npm and npx during install of node (requires rsync)
+  -q, --quiet           Disable curl output (if available)
+  -d, --download        Download only
+  -a, --arch            Override system architecture
+  --all                 ls-remote displays all matches instead of last 20
+  --insecure            Turn off certificate checking for https requests (may be needed from behind a proxy server)
+  --use-xz/--no-use-xz  Override automatic detection of xz support and enable/disable use of xz compressed node downloads.
+
+Aliases:
+
+  which: bin
+  run: use, as
+  ls: list
+  lsr: ls-remote
+  rm: -
+  lts: stable
+  latest: current
+
+Versions:
+
+  Numeric version numbers can be complete or incomplete, with an optional leading 'v'.
+  Versions can also be specified by label, or codename,
+  and other downloadable releases by <remote-folder>/<version>
+
+    4.9.1, 8, v6.1    Numeric versions
+    lts               Newest Long Term Support official release
+    latest, current   Newest official release
+    auto              Read version from file: .n-node-version, .node-version, .nvmrc, or package.json
+    engine            Read version from package.json
+    boron, carbon     Codenames for release streams
+    lts_latest        node support aliases
+
+    and nightly, rc/10 et al
+
+EOF
+}
+
+err_no_installed_print_help() {
+  display_help
+  abort "no downloaded versions yet, see above help for commands"
+}
+
+#
+# Synopsis: next_version_installed selected_version
+# Output version after selected (which may be blank under some circumstances).
+#
+
+function next_version_installed() {
+  display_cache_versions | n_grep "$1" -A 1 | tail -n 1
+}
+
+#
+# Synopsis: prev_version_installed selected_version
+# Output version before selected  (which may be blank under some circumstances).
+#
+
+function prev_version_installed() {
+  display_cache_versions | n_grep "$1" -B 1 | head -n 1
+}
+
+#
+# Output n version.
+#
+
+display_n_version() {
+  echo "$VERSION" && exit 0
+}
+
+#
+# Synopsis: set_active_node
+# Checks cached downloads for a binary matching the active node.
+# Globals modified:
+# - g_active_node
+#
+
+function set_active_node() {
+  g_active_node=
+  local node_path="$(command -v node)"
+  if [[ -x "${node_path}" ]]; then
+    local installed_version=$(node --version)
+    installed_version=${installed_version#v}
+    for dir in "${CACHE_DIR}"/*/ ; do
+      local folder_name="${dir%/}"
+      folder_name="${folder_name##*/}"
+      if diff &> /dev/null \
+        "${CACHE_DIR}/${folder_name}/${installed_version}/bin/node" \
+        "${node_path}" ; then
+        g_active_node="${folder_name}/${installed_version}"
+        break
+      fi
+    done
+  fi
+}
+
+#
+# Display sorted versions directories paths.
+#
+
+display_versions_paths() {
+  find "$CACHE_DIR" -maxdepth 2 -type d \
+    | sed 's|'"$CACHE_DIR"'/||g' \
+    | n_grep -E "/[0-9]+\.[0-9]+\.[0-9]+" \
+    | sed 's|/|.|' \
+    | sort -k 1,1 -k 2,2n -k 3,3n -k 4,4n -t . \
+    | sed 's|\.|/|'
+}
+
+#
+# Display installed versions with <selected>
+#
+
+display_versions_with_selected() {
+  local selected="$1"
+  echo
+  for version in $(display_versions_paths); do
+    if test "$version" = "$selected"; then
+      printf "  ${SGR_CYAN}ο${SGR_RESET} %s\n" "$version"
+    else
+      printf "    ${SGR_FAINT}%s${SGR_RESET}\n" "$version"
+    fi
+  done
+  echo
+  printf "Use up/down arrow keys to select a version, return key to install, d to delete, q to quit"
+}
+
+#
+# Synopsis: display_cache_versions
+#
+
+function display_cache_versions() {
+  for folder_and_version in $(display_versions_paths); do
+    echo "${folder_and_version}"
+  done
+}
+
+#
+# Display current node --version and others installed.
+#
+
+menu_select_cache_versions() {
+  enter_fullscreen
+  set_active_node
+  local selected="${g_active_node}"
+
+  clear
+  display_versions_with_selected "${selected}"
+
+  trap handle_sigint INT
+  trap handle_sigtstp SIGTSTP
+
+  ESCAPE_SEQ=$'\033'
+  UP=$'A'
+  DOWN=$'B'
+
+  while true; do
+    read -rsn 1 key
+    case "$key" in
+      "$ESCAPE_SEQ")
+        # Handle ESC sequences followed by other characters, i.e. arrow keys
+        read -rsn 1 -t 1 tmp
+        if [[ "$tmp" == "[" ]]; then
+          read -rsn 1 -t 1 arrow
+          case "$arrow" in
+            "$UP")
+              clear
+              selected="$(prev_version_installed "${selected}")"
+              display_versions_with_selected "${selected}"
+              ;;
+            "$DOWN")
+              clear
+              selected="$(next_version_installed "${selected}")"
+              display_versions_with_selected "${selected}"
+              ;;
+          esac
+        fi
+        ;;
+      "d")
+        if [[ -n "${selected}" ]]; then
+          clear
+          # Note: prev/next is constrained to min/max
+          local after_delete_selection="$(next_version_installed "${selected}")"
+          if [[ "${after_delete_selection}" == "${selected}"  ]]; then
+            after_delete_selection="$(prev_version_installed "${selected}")"
+          fi
+          remove_versions "${selected}"
+
+          if [[ "${after_delete_selection}" == "${selected}" ]]; then
+            clear
+            leave_fullscreen
+            echo "All downloaded versions have been deleted from cache."
+            exit
+          fi
+
+          selected="${after_delete_selection}"
+          display_versions_with_selected "${selected}"
+        fi
+        ;;
+      "k")
+        clear
+        selected="$(prev_version_installed "${selected}")"
+        display_versions_with_selected "${selected}"
+        ;;
+      "j")
+        clear
+        selected="$(next_version_installed "${selected}")"
+        display_versions_with_selected "${selected}"
+        ;;
+      "q")
+        clear
+        leave_fullscreen
+        exit
+        ;;
+      "")
+        # enter key returns empty string
+        leave_fullscreen
+        [[ -n "${selected}" ]] && activate "${selected}"
+        exit
+        ;;
+    esac
+  done
+}
+
+#
+# Move up a line and erase.
+#
+
+erase_line() {
+  printf "\033[1A\033[2K"
+}
+
+#
+# Disable PaX mprotect for <binary>
+#
+
+disable_pax_mprotect() {
+  test -z "$1" && abort "binary required"
+  local binary="$1"
+
+  # try to disable mprotect via XATTR_PAX header
+  local PAXCTL="$(PATH="/sbin:/usr/sbin:$PATH" command -v paxctl-ng 2>&1)"
+  local PAXCTL_ERROR=1
+  if [ -x "$PAXCTL" ]; then
+    $PAXCTL -l && $PAXCTL -m "$binary" >/dev/null 2>&1
+    PAXCTL_ERROR="$?"
+  fi
+
+  # try to disable mprotect via PT_PAX header
+  if [ "$PAXCTL_ERROR" != 0 ]; then
+    PAXCTL="$(PATH="/sbin:/usr/sbin:$PATH" command -v paxctl 2>&1)"
+    if [ -x "$PAXCTL" ]; then
+      $PAXCTL -Cm "$binary" >/dev/null 2>&1
+    fi
+  fi
+}
+
+#
+# Activate <version>
+#
+
+activate() {
+  local version="$1"
+  local dir="$CACHE_DIR/$version"
+  local original_node="$(command -v node)"
+
+  # Remove old npm to avoid potential issues with simple overwrite.
+  if [[ -z "${N_PRESERVE_NPM}" && -d "$dir/lib/node_modules/npm" ]]; then
+    if test -d "$N_PREFIX/lib/node_modules/npm"; then
+      rm -rf "$N_PREFIX/lib/node_modules/npm"
+    fi
+  fi
+  # Remove old node to avoid potential problems with firewall getting confused on Darwin by overwrite.
+  rm -f "$N_PREFIX/bin/node"
+  # Copy (lib before bin to avoid error messages on Darwin when cp over dangling link)
+  for subdir in lib bin include share; do
+    if [[ -n "${N_PRESERVE_NPM}" ]]; then
+      rsync --recursive --archive --keep-dirlinks --exclude=npm --exclude=npx "${dir}/${subdir}" "${N_PREFIX}"
+    elif test -L "$N_PREFIX/$subdir"; then
+      find "$dir/$subdir" -mindepth 1 -maxdepth 1 -exec cp -fR "{}" "$N_PREFIX/$subdir" \;
+    else
+      cp -fR "$dir/$subdir" "$N_PREFIX"
+    fi
+  done
+  local installed_node="${N_PREFIX}/bin/node"
+  disable_pax_mprotect "${installed_node}"
+
+  local active_node="$(command -v node)"
+  if [[ -e "${active_node}" && -e "${installed_node}" && "${active_node}" != "${installed_node}" ]]; then
+    # Installed and active are different which might be a PATH problem. List both to give user some clues.
+    log "installed" "$("${installed_node}" --version) to ${installed_node}"
+    log "active" "$("${active_node}" --version) at ${active_node}"
+  else
+    local npm_version_str=""
+    local installed_npm="${N_PREFIX}/bin/npm"
+    local active_npm="$(command -v npm)"
+    if [[ -z "${N_PRESERVE_NPM}" && -e "${active_npm}" && -e "${installed_npm}" && "${active_npm}" = "${installed_npm}" ]]; then
+      npm_version_str=" (with npm $(npm --version))"
+    fi
+
+    log "installed" "$("${installed_node}" --version)${npm_version_str}"
+
+    # Extra tips for changed location.
+    if [[ -e "${active_node}" && -e "${original_node}" && "${active_node}" != "${original_node}" ]]; then
+      printf '\nNote: the node command changed location and the old location may be remembered in your current shell.\n'
+      log old "${original_node}"
+      log new "${active_node}"
+      # shellcheck disable=SC2016
+      printf 'To reset the command location hash either start a new shell, or execute PATH="$PATH"\n'
+    fi
+  fi
+}
+
+#
+# Install <version>
+#
+
+install() {
+  [[ -z "$1" ]] && abort "version required"
+  local version
+  version="$(display_latest_resolved_version "$1")" || return 2
+  [[ -n "${version}" ]] || abort "no version found for '$1'"
+  update_mirror_settings_for_version "$1"
+  update_xz_settings_for_version "${version}"
+
+  local dir="${CACHE_DIR}/${g_mirror_folder_name}/${version}"
+
+  if test "$N_USE_XZ" = "true"; then
+    local tarflag="-Jx"
+  else
+    local tarflag="-zx"
+  fi
+
+  if test -d "$dir"; then
+    if [[ ! -e "$dir/n.lock" ]] ; then
+      if "$ACTIVATE" ; then
+        activate "${g_mirror_folder_name}/${version}"
+      fi
+      exit
+    fi
+  fi
+
+  log installing "${g_mirror_folder_name}-v$version"
+
+  local url="$(tarball_url "$version")"
+  is_ok "${url}" || abort "download preflight failed for '$version' (${url})"
+
+  log mkdir "$dir"
+  mkdir -p "$dir" || abort "sudo required (or change ownership, or define N_PREFIX)"
+  touch "$dir/n.lock"
+
+  cd "${dir}" || abort "Failed to cd to ${dir}"
+
+  log fetch "$url"
+  do_get "${url}" | tar "$tarflag" --strip-components=1 --no-same-owner
+  if [[ "${PIPESTATUS[0]}" -ne 0 ]]; then
+    abort "failed to download archive for $version"
+  fi
+  [ "$GET_SHOWS_PROGRESS" = "true" ] && erase_line
+  rm -f "$dir/n.lock"
+
+  disable_pax_mprotect bin/node
+
+  if "$ACTIVATE" ; then
+    activate "${g_mirror_folder_name}/$version"
+  fi
+}
+
+#
+# Set curl to quiet (silent) mode.
+#
+
+set_quiet() {
+  command -v curl > /dev/null && CURL_OPTIONS+=( "--silent" ) && GET_SHOWS_PROGRESS="false"
+}
+
+#
+# Synopsis: do_get [option...] url
+# Call curl or wget with combination of global and passed options.
+#
+
+function do_get() {
+  if command -v curl &> /dev/null; then
+    curl "${CURL_OPTIONS[@]}" "$@"
+  elif command -v wget &> /dev/null; then
+    wget "${WGET_OPTIONS[@]}" "$@"
+  else
+    abort "curl or wget command required"
+  fi
+}
+
+#
+# Synopsis: do_get_index [option...] url
+# Call curl or wget with combination of global and passed options,
+# with options tweaked to be more suitable for getting index.
+#
+
+function do_get_index() {
+  if command -v curl &> /dev/null; then
+    # --silent to suppress progress et al
+    curl --silent --compressed "${CURL_OPTIONS[@]}" "$@"
+  elif command -v wget &> /dev/null; then
+    wget "${WGET_OPTIONS[@]}" "$@"
+  else
+    abort "curl or wget command required"
+  fi
+}
+
+#
+# Synopsis: remove_versions version ...
+#
+
+function remove_versions() {
+  [[ -z "$1" ]] && abort "version(s) required"
+  while [[ $# -ne 0 ]]; do
+    local version
+    version="$(display_latest_resolved_version "$1")" || break
+    if [[ -n "${version}" ]]; then
+      update_mirror_settings_for_version "$1"
+      local dir="${CACHE_DIR}/${g_mirror_folder_name}/${version}"
+      if [[ -s "${dir}" ]]; then
+        rm -rf "${dir}"
+      else
+        echo "$1 (${version}) not in downloads cache"
+      fi
+    else
+      echo "No version found for '$1'"
+    fi
+    shift
+  done
+}
+
+#
+# Synopsis: prune_cache
+#
+
+function prune_cache() {
+  set_active_node
+
+  for folder_and_version in $(display_versions_paths); do
+    if [[ "${folder_and_version}" != "${g_active_node}" ]]; then
+      echo "${folder_and_version}"
+      rm -rf "${CACHE_DIR:?}/${folder_and_version}"
+    fi
+  done
+}
+
+#
+# Synopsis: find_cached_version version
+# Finds cache directory for resolved version.
+# Globals modified:
+# - g_cached_version
+
+function find_cached_version() {
+  [[ -z "$1" ]] && abort "version required"
+  local version
+  version="$(display_latest_resolved_version "$1")" || exit 1
+  [[ -n "${version}" ]] || abort "no version found for '$1'"
+
+  update_mirror_settings_for_version "$1"
+  g_cached_version="${CACHE_DIR}/${g_mirror_folder_name}/${version}"
+  [[ -d "${g_cached_version}" ]] || abort "'$1' (${version}) not in downloads cache"
+}
+
+
+#
+# Synopsis: display_bin_path_for_version version
+#
+
+function display_bin_path_for_version() {
+  find_cached_version "$1"
+  echo "${g_cached_version}/bin/node"
+}
+
+#
+# Synopsis: run_with_version version [args...]
+# Run the given <version> of node with [args ..]
+#
+
+function run_with_version() {
+  find_cached_version "$1"
+  shift # remove version from parameters
+  exec "${g_cached_version}/bin/node" "$@"
+}
+
+#
+# Synopsis: exec_with_version <version> command [args...]
+# Modify the path to include <version> and execute command.
+#
+
+function exec_with_version() {
+  find_cached_version "$1"
+  shift # remove version from parameters
+  PATH="${g_cached_version}/bin:$PATH" exec "$@"
+}
+
+#
+# Synopsis: is_ok url
+# Check the HEAD response of <url>.
+#
+
+function is_ok() {
+  # Note: both curl and wget can follow redirects, as present on some mirrors (e.g. https://npm.taobao.org/mirrors/node).
+  # The output is complicated with redirects, so keep it simple and use command status rather than parse output.
+  if command -v curl &> /dev/null; then
+    do_get --silent --head "$1" > /dev/null || return 1
+  else
+    do_get --spider "$1" > /dev/null || return 1
+  fi
+}
+
+#
+# Synopsis: can_use_xz
+# Test system to see if xz decompression is supported by tar.
+#
+
+function can_use_xz() {
+  # Be conservative and only enable if xz is likely to work. Unfortunately we can't directly query tar itself.
+  # For research, see https://github.com/shadowspawn/nvh/issues/8
+  local uname_s="$(uname -s)"
+  if [[ "${uname_s}" = "Linux" ]] && command -v xz &> /dev/null ; then
+    # tar on linux is likely to support xz if it is available as a command
+    return 0
+  elif [[ "${uname_s}" = "Darwin" ]]; then
+    local macos_version="$(sw_vers -productVersion)"
+    local macos_major_version="$(echo "${macos_version}" | cut -d '.' -f 1)"
+    local macos_minor_version="$(echo "${macos_version}" | cut -d '.' -f 2)"
+    if [[ "${macos_major_version}" -gt 10 || "${macos_minor_version}" -gt 8 ]]; then
+      # tar on recent Darwin has xz support built-in
+      return 0
+    fi
+  fi
+  return 2 # not supported
+}
+
+#
+# Synopsis: display_tarball_platform
+#
+
+function display_tarball_platform() {
+  # https://en.wikipedia.org/wiki/Uname
+
+  local os="unexpected_os"
+  local uname_a="$(uname -a)"
+  case "${uname_a}" in
+    Linux*) os="linux" ;;
+    Darwin*) os="darwin" ;;
+    SunOS*) os="sunos" ;;
+    AIX*) os="aix" ;;
+    CYGWIN*) >&2 echo_red "Cygwin is not supported by n" ;;
+    MINGW*) >&2 echo_red "Git BASH (MSYS) is not supported by n" ;;
+  esac
+
+  local arch="unexpected_arch"
+  local uname_m="$(uname -m)"
+  case "${uname_m}" in
+    x86_64) arch=x64 ;;
+    i386 | i686) arch="x86" ;;
+    aarch64) arch=arm64 ;;
+    armv8l) arch=arm64 ;; # armv8l probably supports arm64, and there is no specific armv8l build so give it a go
+    *)
+      # e.g. armv6l, armv7l, arm64
+      arch="${uname_m}"
+      ;;
+  esac
+  # Override from command line.
+  [ -n "$ARCH" ] && arch="$ARCH"
+  # Fallback to x64 if autodetecting on Apple M1, native versions not available yet.
+  [[ -z "$ARCH" && "$os" == "darwin" && "$arch" == "arm64" ]] && arch=x64
+
+  echo "${os}-${arch}"
+}
+
+#
+# Synopsis: display_compatible_file_field
+# display <file> for current platform, as per <file> field in index.tab, which is different than actual download
+#
+
+function display_compatible_file_field {
+  local compatible_file_field="$(display_tarball_platform)"
+  if [[ "${compatible_file_field}" =~ darwin-(.*) ]]; then
+    compatible_file_field="osx-${BASH_REMATCH[1]}-tar"
+  fi
+  echo "${compatible_file_field}"
+}
+
+#
+# Synopsis: tarball_url version
+#
+
+function tarball_url() {
+  local version="$1"
+  local ext=gz
+  [ "$N_USE_XZ" = "true" ] && ext="xz"
+  echo "${g_mirror_url}/v${version}/node-v${version}-$(display_tarball_platform).tar.${ext}"
+}
+
+#
+# Synopsis: display_file_node_version filename
+#
+
+function display_file_node_version() {
+  local filepath="$1"
+  trace_log "found" "${filepath}"
+  # read returns a non-zero status but does still work if there is no line ending
+  local version
+  <"${filepath}" read -r version
+  # trim possible trailing \d from a Windows created file
+  version="${version%%[[:space:]]}"
+  trace_log "read" "${version}"
+  echo "${version}"
+}
+
+#
+# Synopsis: display_package_engine_version
+#
+
+function display_package_engine_version() {
+  local filepath="$1"
+  trace_log "found" "${filepath}"
+  command -v node &> /dev/null || abort "an active version of node is required to read 'engines' from package.json"
+  local range
+  range="$(node -e "package = require('${filepath}'); if (package && package.engines && package.engines.node) console.log(package.engines.node)")"
+  trace_log "read" "${range}"
+  if [[ -z "${range}" || "*" == "${range}" ]]; then
+    trace_log "target" "current"
+    echo "current"
+    return
+  fi
+
+  local version
+  if [[ "${range}" =~ ^([>~^=]|\>\=)?v?([0-9]+(\.[0-9]+){0,2})(.[xX*])?$ ]]; then
+    local operator="${BASH_REMATCH[1]}"
+    version="${BASH_REMATCH[2]}"
+    case "${operator}" in
+      '' | =) ;;
+      \> | \>=) version="current" ;;
+      \~) [[ "${version}" =~ ^([0-9]+\.[0-9]+)\.[0-9]+$ ]] && version="${BASH_REMATCH[1]}" ;;
+      ^) [[ "${version}" =~ ^([0-9]+) ]] && version="${BASH_REMATCH[1]}" ;;
+    esac
+    trace_log "target" "${version}"
+  else
+    command -v npx &> /dev/null || abort "an active version of npx is required to use complex 'engine' ranges from package.json"
+    trace_log "resolving" "${range}"
+    local version_per_line="$(n lsr --all)"
+    local versions_one_line=$(echo "${version_per_line}" | tr '\n' ' ')
+    # Using semver@7 so works with older versions of node.
+    # shellcheck disable=SC2086
+    version=$(npm_config_yes=true npx --quiet semver@7 -r "${range}" ${versions_one_line} | tail -n 1)
+  fi
+  echo "${version}"
+}
+
+#
+# Synopsis: display_nvmrc_version
+#
+
+function display_nvmrc_version() {
+  local filepath="$1"
+  trace_log "found" "${filepath}"
+  local version
+  <"${filepath}" read -r version
+  trace_log "read" "${version}"
+  # Translate from nvm aliases
+  case "${version}" in
+    lts/\*) version="lts" ;;
+    lts/*) version="${version:4}" ;;
+    node) version="current" ;;
+    *) ;;
+  esac
+  echo "${version}"
+}
+
+#
+# Synopsis: display_engine_version [error-message]
+#
+
+function display_engine_version() {
+  local error_message="${1-package.json not found}"
+  local parent
+  parent="${PWD}"
+  while [[ -n "${parent}" ]]; do
+    if [[ -e "${parent}/package.json" ]]; then
+      display_package_engine_version "${parent}/package.json"
+    else
+      parent=${parent%/*}
+      continue
+    fi
+    break
+  done
+  [[ -n "${parent}" ]] || abort "${error_message}"
+}
+
+#
+# Synopsis: display_auto_version
+#
+
+function display_auto_version() {
+  # Search for a version control file first
+  local parent
+  parent="${PWD}"
+  while [[ -n "${parent}" ]]; do
+    if [[ -e "${parent}/.n-node-version" ]]; then
+      display_file_node_version "${parent}/.n-node-version"
+    elif [[ -e "${parent}/.node-version" ]]; then
+      display_file_node_version "${parent}/.node-version"
+    elif [[ -e "${parent}/.nvmrc" ]]; then
+      display_nvmrc_version "${parent}/.nvmrc"
+    else
+      parent=${parent%/*}
+      continue
+    fi
+    break
+  done
+  # Fallback to package.json
+  [[ -n "${parent}" ]] || display_engine_version "no file found for auto version (.n-node-version, .node-version, .nvmrc, or package.json)"
+}
+#
+# Synopsis: display_latest_resolved_version version
+#
+
+function display_latest_resolved_version() {
+  local version=${1}
+  # auto and engine make sense for local use and not much for ls-remote, so handled here rather than display_remote_versions
+  if [[ "${version}" = "auto" ]]; then
+    version="$(display_auto_version)" || return 2
+  fi
+  if [[ "${version}" = "engine" ]]; then
+    version="$(display_engine_version)" || return 2
+  fi
+  simple_version=${version#node/} # Only place supporting node/ [sic]
+  if is_exact_numeric_version "${simple_version}"; then
+    # Just numbers, already resolved, no need to lookup first.
+    simple_version="${simple_version#v}"
+    echo "${simple_version}"
+  else
+    # Complicated recognising exact version, KISS and lookup.
+    N_MAX_REMOTE_MATCHES=1 display_remote_versions "$version"
+  fi
+}
+
+#
+# Synopsis: display_remote_index
+# index.tab reference: https://github.com/nodejs/nodejs-dist-indexer
+# Index fields are: version	date	files	npm	v8	uv	zlib	openssl	modules	lts security
+# KISS and just return fields we currently care about: version files lts
+#
+
+display_remote_index() {
+  local index_url="${g_mirror_url}/index.tab"
+  echo "index_url is ${index_url}"
+  # tail to remove header line
+  do_get_index "${index_url}" | tail -n +2 | cut -f 1,3,10
+  if [[ "${PIPESTATUS[0]}" -ne 0 ]]; then
+    # Reminder: abort will only exit subshell, but consistent error display
+    abort "failed to download version index (${index_url})"
+  fi
+}
+
+#
+# Synopsis: display_match_limit limit
+#
+
+function display_match_limit(){
+  if [[ "$1" -gt 1 && "$1" -lt 32000 ]]; then
+    echo "Listing remote... Displaying $1 matches (use --all to see all)."
+  fi
+}
+
+#
+# Synopsis: display_remote_versions version
+#
+
+function display_remote_versions() {
+  local version="$1"
+  update_mirror_settings_for_version "${version}"
+  local match='.'
+  local match_count="${N_MAX_REMOTE_MATCHES}"
+  if is_node_support_version "${version}"; then
+    version="$(display_latest_node_support_alias "${version}")"
+    match_count=1
+  fi
+  if [[ -z "${version}" ]]; then
+    match='.'
+  elif [[ "${version}" = "lts" || "${version}" = "stable" ]]; then
+    match_count=1
+    # Codename is last field, first one with a name is newest lts
+    match="${TAB_CHAR}[a-zA-Z]+\$"
+  elif [[ "${version}" = "latest" || "${version}" = "current" ]]; then
+    match_count=1
+    match='.'
+  elif is_numeric_version "${version}"; then
+    version="v${version#v}"
+    # Avoid restriction message if exact version
+    is_exact_numeric_version "${version}" && match_count=1
+    # Quote any dots in version so they are literal for expression
+    match="${version//\./\.}"
+    # Avoid 1.2 matching 1.23
+    match="^${match}[^0-9]"
+  elif is_lts_codename "${version}"; then
+    # Capitalise (could alternatively make grep case insensitive)
+    codename="$(echo "${version:0:1}" | tr '[:lower:]' '[:upper:]')${version:1}"
+    # Codename is last field
+    match="${TAB_CHAR}${codename}\$"
+  elif is_download_folder "${version}"; then
+    match='.'
+  elif is_download_version "${version}"; then
+    version="${version#${g_mirror_folder_name}/}"
+    if [[ "${version}" = "latest" || "${version}" = "current" ]]; then
+      match_count=1
+      match='.'
+    else
+      version="v${version#v}"
+      match="${version//\./\.}"
+      match="^${match}" # prefix
+      if is_numeric_version "${version}"; then
+        # Exact numeric match
+        match="${match}[^0-9]"
+      fi
+    fi
+  else
+    abort "invalid version '$1'"
+  fi
+  display_match_limit "${match_count}"
+
+  # Implementation notes:
+  # - using awk rather than head so do not close pipe early on curl
+  # - restrict search to compatible files as not always available, or not at same time
+  # - return status of curl command (i.e. PIPESTATUS[0])
+  display_remote_index \
+    | n_grep -E "$(display_compatible_file_field)" \
+    | n_grep -E "${match}" \
+    | awk "NR<=${match_count}" \
+    | cut -f 1 \
+    | n_grep -E -o '[^v].*'
+  return "${PIPESTATUS[0]}"
+}
+
+#
+# Synopsis: delete_with_echo target
+#
+
+function delete_with_echo() {
+  if [[ -e "$1" ]]; then
+    echo "$1"
+    rm -rf "$1"
+  fi
+}
+
+#
+# Synopsis: uninstall_installed
+# Uninstall the installed node and npm (leaving alone the cache),
+# so undo install, and may expose possible system installed versions.
+#
+
+uninstall_installed() {
+  # npm: https://docs.npmjs.com/misc/removing-npm
+  #   rm -rf /usr/local/{lib/node{,/.npm,_modules},bin,share/man}/npm*
+  # node: https://stackabuse.com/how-to-uninstall-node-js-from-mac-osx/
+  # Doing it by hand rather than scanning cache, so still works if cache deleted first.
+  # This covers tarballs for at least node 4 through 10.
+
+  while true; do
+      read -r -p "Do you wish to delete node and npm from ${N_PREFIX}? " yn
+      case $yn in
+          [Yy]* ) break ;;
+          [Nn]* ) exit ;;
+          * ) echo "Please answer yes or no.";;
+      esac
+  done
+
+  echo ""
+  echo "Uninstalling node and npm"
+  delete_with_echo "${N_PREFIX}/bin/node"
+  delete_with_echo "${N_PREFIX}/bin/npm"
+  delete_with_echo "${N_PREFIX}/bin/npx"
+  delete_with_echo "${N_PREFIX}/include/node"
+  delete_with_echo "${N_PREFIX}/lib/dtrace/node.d"
+  delete_with_echo "${N_PREFIX}/lib/node_modules/npm"
+  delete_with_echo "${N_PREFIX}/share/doc/node"
+  delete_with_echo "${N_PREFIX}/share/man/man1/node.1"
+  delete_with_echo "${N_PREFIX}/share/systemtap/tapset/node.stp"
+}
+
+#
+# Synopsis: show_permission_suggestions
+#
+
+function show_permission_suggestions() {
+  echo "Suggestions:"
+  echo "- run n with sudo, or"
+  echo "- define N_PREFIX to a writeable location, or"
+}
+
+#
+# Synopsis: show_diagnostics
+# Show environment and check for common problems.
+#
+
+function show_diagnostics() {
+  echo "This information is to help you diagnose issues, and useful when reporting an issue."
+  echo "Note: some output may contain passwords. Redact before sharing."
+
+  printf "\n\nCOMMAND LOCATIONS AND VERSIONS\n"
+
+  printf "\nbash\n"
+  command -v bash && bash --version
+
+  printf "\nn\n"
+  command -v n && n --version
+
+  printf "\nnode\n"
+  if command -v node &> /dev/null; then
+    command -v node && node --version
+    node -e 'if (process.versions.v8) console.log("JavaScript engine: v8");'
+
+    printf "\nnpm\n"
+    command -v npm && npm --version
+  fi
+
+  printf "\ntar\n"
+  if command -v tar &> /dev/null; then
+    command -v tar && tar --version
+  else
+    echo_red "tar not found. Needed for extracting downloads."
+  fi
+
+  printf "\ncurl or wget\n"
+  if command -v curl &> /dev/null; then
+    command -v curl && curl --version
+  elif command -v wget &> /dev/null; then
+    command -v wget && wget --version
+  else
+    echo_red "Neither curl nor wget found. Need one of them for downloads."
+  fi
+
+  printf "\nrsync:\n"
+  if command -v rsync &> /dev/null; then
+    command -v rsync && rsync --version
+  else
+    printf "rsync not found. (Needed for preserving npm during install.)\n"
+  fi
+
+  printf "\nuname\n"
+  uname -a
+
+  printf "\n\nSETTINGS\n"
+
+  printf "\nn\n"
+  echo "node mirror: ${N_NODE_MIRROR}"
+  echo "node downloads mirror: ${N_NODE_DOWNLOAD_MIRROR}"
+  echo "install destination: ${N_PREFIX}"
+  [[ -n "${N_PREFIX}" ]] && echo "PATH: ${PATH}"
+  echo "ls-remote max matches: ${N_MAX_REMOTE_MATCHES}"
+   [[ -n "${N_PRESERVE_NPM}" ]] && echo "installs preserve npm by default"
+
+  printf "\nProxy\n"
+  # disable "var is referenced but not assigned": https://github.com/koalaman/shellcheck/wiki/SC2154
+  # shellcheck disable=SC2154
+  [[ -n "${http_proxy}" ]] && echo "http_proxy: ${http_proxy}"
+  # shellcheck disable=SC2154
+  [[ -n "${https_proxy}" ]] && echo "https_proxy: ${https_proxy}"
+  if command -v curl &> /dev/null; then
+    # curl supports lower case and upper case!
+    # shellcheck disable=SC2154
+    [[ -n "${all_proxy}" ]] && echo "all_proxy: ${all_proxy}"
+    [[ -n "${ALL_PROXY}" ]] && echo "ALL_PROXY: ${ALL_PROXY}"
+    [[ -n "${HTTP_PROXY}" ]] && echo "HTTP_PROXY: ${HTTP_PROXY}"
+    [[ -n "${HTTPS_PROXY}" ]] && echo "HTTPS_PROXY: ${HTTPS_PROXY}"
+    if [[ -e "${CURL_HOME}/.curlrc" ]]; then
+       echo "have \$CURL_HOME/.curlrc"
+    elif [[ -e "${HOME}/.curlrc" ]]; then
+      echo "have \$HOME/.curlrc"
+    fi
+  elif command -v wget &> /dev/null; then
+    if [[ -e "${WGETRC}" ]]; then
+      echo "have \$WGETRC"
+    elif [[ -e "${HOME}/.wgetrc" ]]; then
+      echo "have \$HOME/.wgetrc"
+    fi
+  fi
+
+  printf "\n\nCHECKS\n"
+
+  printf "\nChecking n install destination is in PATH...\n"
+  local install_bin="${N_PREFIX}/bin"
+  local path_wth_guards=":${PATH}:"
+  if [[ "${path_wth_guards}" =~ :${install_bin}/?: ]]; then
+    printf "good\n"
+  else
+    echo_red "'${install_bin}' is not in PATH"
+  fi
+  if command -v node &> /dev/null; then
+    printf "\nChecking n install destination priority in PATH...\n"
+    local node_dir="$(dirname "$(command -v node)")"
+
+    local index=0
+    local path_entry
+    local path_entries
+    local install_bin_index=0
+    local node_index=999
+    IFS=':' read -ra path_entries <<< "${PATH}"
+    for path_entry in "${path_entries[@]}"; do
+      (( index++ ))
+      [[ "${path_entry}" =~ ^${node_dir}/?$ ]] && node_index="${index}"
+      [[ "${path_entry}" =~ ^${install_bin}/?$ ]] && install_bin_index="${index}"
+    done
+    if [[ "${node_index}" -lt "${install_bin_index}" ]]; then
+      echo_red "There is a version of node installed which will be found in PATH before the n installed version."
+    else
+      printf "good\n"
+    fi
+  fi
+
+  printf "\nChecking permissions for cache folder...\n"
+  # Most likely problem is ownership rather than than permissions as such.
+  local cache_root="${N_PREFIX}/n"
+  if [[ -e "${N_PREFIX}" && ! -w "${N_PREFIX}" && ! -e "${cache_root}" ]]; then
+    echo_red "You do not have write permission to create: ${cache_root}"
+    show_permission_suggestions
+    echo "- make a folder you own:"
+    echo "      sudo mkdir -p \"${cache_root}\""
+    echo "      sudo chown $(whoami) \"${cache_root}\""
+  elif [[ -e "${cache_root}" && ! -w "${cache_root}" ]]; then
+    echo_red "You do not have write permission to: ${cache_root}"
+    show_permission_suggestions
+    echo "- change folder ownership to yourself:"
+    echo "      sudo chown -R $(whoami) \"${cache_root}\""
+  elif [[ ! -e "${cache_root}" ]]; then
+    echo "Cache folder does not exist: ${cache_root}"
+    echo "This is normal if you have not done an install yet, as cache is only created when needed."
+  elif [[ -e "${CACHE_DIR}" && ! -w "${CACHE_DIR}" ]]; then
+    echo_red "You do not have write permission to: ${CACHE_DIR}"
+    show_permission_suggestions
+    echo "- change folder ownership to yourself:"
+    echo "      sudo chown -R $(whoami) \"${CACHE_DIR}\""
+  else
+    echo "good"
+  fi
+
+  if [[ -e "${N_PREFIX}" ]]; then
+    # Most likely problem is ownership rather than than permissions as such.
+    printf "\nChecking permissions for install folders...\n"
+    local install_writeable="true"
+    for subdir in bin lib include share; do
+      if [[ -e "${N_PREFIX}/${subdir}" && ! -w "${N_PREFIX}/${subdir}" ]]; then
+        install_writeable="false"
+        echo_red "You do not have write permission to: ${N_PREFIX}/${subdir}"
+        break
+      fi
+    done
+    if [[ "${install_writeable}" = "true" ]]; then
+      echo "good"
+    else
+      show_permission_suggestions
+      echo "- change folder ownerships to yourself:"
+      echo "      (cd \"${N_PREFIX}\" && sudo chown -R $(whoami) bin lib include share)"
+    fi
+  fi
+
+  printf "\nChecking mirror is reachable...\n"
+  if is_ok "${N_NODE_MIRROR}/"; then
+    printf "good\n"
+  else
+    echo_red "mirror not reachable"
+    printf "Showing failing command and output\n"
+    if command -v curl &> /dev/null; then
+      ( set -x; do_get --head "${N_NODE_MIRROR}/" )
+    else
+      ( set -x; do_get --spider "${N_NODE_MIRROR}/" )
+    printf "\n"
+   fi
+  fi
+}
+
+#
+# Handle arguments.
+#
+
+# First pass. Process the options so they can come before or after commands,
+# particularly for `n lsr --all` and `n install --arch x686`
+# which feel pretty natural.
+
+unprocessed_args=()
+
+while [[ $# -ne 0 ]]; do
+  case "$1" in
+    --all) N_MAX_REMOTE_MATCHES=32000 ;;
+    -V|--version) display_n_version ;;
+    -h|--help|help) display_help; exit ;;
+    -q|--quiet) set_quiet ;;
+    -d|--download) ACTIVATE=false ;;
+    --insecure) set_insecure ;;
+    -p|--preserve) N_PRESERVE_NPM="true" ;;
+    --no-preserve) N_PRESERVE_NPM="" ;;
+    --use-xz) N_USE_XZ="true" ;;
+    --no-use-xz) N_USE_XZ="false" ;;
+    --latest) display_remote_versions latest; exit ;;
+    --stable) display_remote_versions lts; exit ;; # [sic] old terminology
+    --lts) display_remote_versions lts; exit ;;
+    -a|--arch) shift; set_arch "$1";; # set arch and continue
+    exec) unprocessed_args=("$@"); break ;;
+    run|as|use) unprocessed_args=("$@"); break ;;
+    *) unprocessed_args+=( "$1" ) ;;
+  esac
+  shift
+done
+
+if [[ -z "${N_USE_XZ+defined}" ]]; then
+  N_USE_XZ="true" # Default to using xz
+  can_use_xz || N_USE_XZ="false"
+fi
+
+set -- "${unprocessed_args[@]}"
+
+if test $# -eq 0; then
+  test -z "$(display_versions_paths)" && err_no_installed_print_help
+  menu_select_cache_versions
+else
+  while test $# -ne 0; do
+    case "$1" in
+      bin|which) display_bin_path_for_version "$2"; exit ;;
+      run|as|use) shift; run_with_version "$@"; exit ;;
+      exec) shift; exec_with_version "$@"; exit ;;
+      doctor) show_diagnostics; exit ;;
+      rm|-) shift; remove_versions "$@"; exit ;;
+      prune) prune_cache; exit ;;
+      latest) install latest; exit ;;
+      stable) install stable; exit ;;
+      lts) install lts; exit ;;
+      ls|list) display_versions_paths; exit ;;
+      lsr|ls-remote|list-remote) shift; display_remote_versions "$1"; exit ;;
+      uninstall) uninstall_installed; exit ;;
+      i|install) shift; install "$1"; exit ;;
+      N_TEST_DISPLAY_LATEST_RESOLVED_VERSION) shift; display_latest_resolved_version "$1"; exit ;;
+      *) install "$1"; exit ;;
+    esac
+    shift
+  done
+fi
diff --git a/installer/files/share/applications/ocoge.desktop b/installer/files/share/applications/ocoge.desktop
new file mode 100644
index 0000000..b924c60
--- /dev/null
+++ b/installer/files/share/applications/ocoge.desktop
@@ -0,0 +1,13 @@
+[Desktop Entry]
+Type=Application
+Version=1.0
+Name=オコゲ
+Comment=大岩産 code generator
+Path=/home/pi/Applications/ocoge
+Exec=npm start
+Icon=ocoge.png
+Categories=Development;IDE;
+Terminal=false
+Encoding=UTF-8
+StartupNotify=true
+
diff --git a/installer/files/share/icons/hicolor/48x48/apps/ocoge.png b/installer/files/share/icons/hicolor/48x48/apps/ocoge.png
new file mode 100644
index 0000000..79fd619
Binary files /dev/null and b/installer/files/share/icons/hicolor/48x48/apps/ocoge.png differ
diff --git a/installer/install.sh b/installer/install.sh
new file mode 100644
index 0000000..c5d7349
--- /dev/null
+++ b/installer/install.sh
@@ -0,0 +1,24 @@
+#!/bin/bash -x
+# Usage: bash install.sh
+
+# install node.js (=electron node version) via n (https://github.com/tj/n)
+sudo bash ./files/n 12.18.3
+# Install latest version of n via npm globally
+sudo npm install -g n
+# install desktop entry
+cp -r ./files/share ~/.local/
+# install binary files if exists
+FILE = "./files/binary.zip"
+if [ -e $FILE ]; then
+  unzip $FILE -d ..
+else
+  echo 'binary.zip not found. plz install manually.'
+fi
+
+# build ocoge
+# prepare for installation electron
+echo 'arch=armv7l' > ~/.npmrc
+cd ..
+npm install
+
+read -p "Press enter to exit: "
\ No newline at end of file
diff --git a/package.json b/package.json
index e57b3e7..cdc9aad 100644
--- a/package.json
+++ b/package.json
@@ -1,30 +1,30 @@
-{
-  "name": "ocoge",
-  "version": "0.1.2",
-  "description": "\"大岩産 Code Generator\" は、Google Blockly ライブラリを使用した、Raspberry Pi 上で動作するブロックプログラム開発・実行環境です。",
-  "main": "index.js",
-  "scripts": {
-    "start": "electron .",
-    "postinstall": "electron-rebuild"
-  },
-  "repository": {
-    "type": "git",
-    "url": "git+https://github.com/ocogeclub/ocoge.git"
-  },
-  "keywords": [],
-  "author": "",
-  "license": "ISC",
-  "bugs": {
-    "url": "https://github.com/ocogeclub/ocoge/issues"
-  },
-  "homepage": "https://github.com/ocogeclub/ocoge#readme",
-  "devDependencies": {
-    "electron": "^11.1.1",
-    "electron-rebuild": "^2.3.4"
-  },
-  "dependencies": {
-    "axios": "^0.21.1",
-    "nodemailer": "^6.4.17",
-    "ocoge_pigpiod": "file:local_modules/ocoge_pigpiod"
-  }
+{
+  "name": "ocoge",
+  "version": "0.1.2",
+  "description": "\"大岩産 Code Generator\" は、Google Blockly ライブラリを使用した、Raspberry Pi 上で動作するブロックプログラム開発・実行環境です。",
+  "main": "index.js",
+  "scripts": {
+    "start": "electron .",
+    "postinstall": "electron-rebuild"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/ocogeclub/ocoge.git"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/ocogeclub/ocoge/issues"
+  },
+  "homepage": "https://github.com/ocogeclub/ocoge#readme",
+  "devDependencies": {
+    "electron": "11.2.1",
+    "electron-rebuild": "^2.3.4"
+  },
+  "dependencies": {
+    "axios": "^0.21.1",
+    "nodemailer": "^6.4.17",
+    "ocoge_pigpiod": "file:local_modules/ocoge_pigpiod"
+  }
 }
\ No newline at end of file