install node/npm on mac os

install

1. nvm

wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh|bash

2. set env var for nvm

sudo vim /etc/profile
#add line followed
export NVM_DIR="$HOME/.nvm" && . "$NVM_DIR/nvm.sh"
source /etc/profile

3. list versions of node

nvm ls-remote
       v11.10.0
       v11.10.1
       v11.11.0
       v11.12.0
       v11.13.0
       v11.14.0
        v12.0.0

4. install node

nvm install v12.0.0
Downloading https://nodejs.org/dist/v12.0.0/node-v12.0.0-darwin-x64.tar.gz...
######################################################################## 100.0%
Computing checksum with shasum -a 256
Checksums matched!
Now using node v12.0.0 (npm v6.9.0)
Creating default alias: default -> v12.0.0

extension

#mirrors
export NVM_NODEJS_ORG_MIRROR=https://npm.taobao.org/mirrors/node npm --registry=https://registry.npm.taobao.org

select node

nvm use v5.9.0

problems

• npm install robotjs

npm WARN enoent ENOENT: no such file or directory, open '/home/mage/package.json'
npm WARN licc No description
npm WARN licc No repository field.
npm WARN licc No README data
npm WARN licc No license field.

solved:
npm init -f
npm install robotjs