downloading node tarball script.sh

#!/bin/bash
set -euxo pipefail

# Downloads a node tarball from https://nodejs.org/dist/ and extracts just
# the binary into the current directory. Chiefly we use this to get a node
# binary for uploading to manifold.

if [[ $# -ne 4 ]]; then
  echo "USAGE: $0 <node_version> <os> <arch> <filename>"
  exit 1
fi

node_version=$1
os=$2
arch=$3
node_base="node-v$node_version-$os-$arch"
out=$(realpath "$4")
cd "$(mktemp -d)"

if [ "$os" == "win" ]; then
  url=https://nodejs.org/dist/v$node_version/$node_base.7z
  curl -fSsLo "$node_base.7z" "$url"
  7z x "$node_base.7z"
  tar -cJf "$out" "$node_base"
else
  url=https://nodejs.org/dist/v$node_version/$node_base.tar.xz
  curl -fSsL "$url" > "$out"
fi