install-node.sh - simple script to fetch and install Node.js releases and nightlies on Linux (x86, x64 & ARM) and OS X

install-node.sh

#!/bin/bash

# Note your /usr/local will need to be writable by the user running it,
# alternatively run it with `sudo`

hasxz=$(which xzcat)
os=$(uname | tr '[A-Z]' '[a-z]')
arch=$(uname -m)
targetdir="/usr/local/"
domain=nodejs.org
tarargs=" --strip-components=1 --exclude ./CHANGELOG.md --exclude ./README.md --exclude ./LICENSE -C ${targetdir}"

[[ "$arch" == "x86_64" ]] && arch=x64
[[ "$arch" == "x686" ]] && arch=x86
[[ "$arch" == "x86" ]] && domain=unofficial-builds.nodejs.org

type=release
line=""
yorn=""

while [[ $# -gt 0 ]]
do
key="$1"
case $key in
    -h|--help)
      echo "Usage: install-node.sh [-h|--nightly] [-l|--line <release line>] [-y|--yes]"
      echo "  Where:"
      echo "  --nightly will fetch the latest nightly version instead of the latest release version"
      echo "  --line <release line> will let you select a major version, e.g. --line 10"
      echo "    (note --line will match as much of the version as you want, e.g. --line 10.12 or --line 10.12.0)"
      echo "  --yes will not promot you for confirmation before installing"
      exit 1
    ;;
    -n|--nightly)
    shift
    ;;
    -y|--yes)
    yorn="y"
    shift
    ;;
    -l|--line)
    line="$2"
    shift
    shift
    ;;
    *)
    shift
    ;;
esac
done

latest=$(curl -sL https://${domain}/download/${type}/index.tab | grep "^v${line}" | awk '/^v[0-9]/{ print $1; exit }')

while true; do
  if [ "X${yorn}" == "Xn" ]; then
    break
  fi

  if [ "X${yorn}" == "Xy" ]; then
    url="https://${domain}/download/${type}/$latest/node-${latest}-${os}-${arch}.tar"
    if [ "X${hasxz}" == "X" ]; then
      url="${url}.gz"
      pipecmd="| tar -zx ${tarargs}"
    else
      url="${url}.xz"
      pipecmd="| xzcat | tar -x ${tarargs}"
    fi
    echo "Downloading and unpacking ${url} to ${targetdir}..."
    bash -c "curl -sL '${url}' ${pipecmd}"
    break
  fi

  echo -n "Download and install Node.js ${latest} (${os}/${arch})? [y/n] "
  yorn=""
  read yorn
done

BTW node-nightly at your finger tips! https://git.io/node-nightly

@hemanth thanks for picking that up, I've fixed the ${arch} bit and removed ${auth}. At one point the script was also able to do N|Solid downloads which were Auth protected at one stage. That's redundant now.