Install Lessjs + CSSLint

Install.sh

#!/bin/bash

# pre install
sudo apt-get install g++ curl libssl-dev apache2-utils
sudo apt-get install git-core
sudo apt-get install python-software-properties

# install nodejs
sudo add-apt-repository ppa:jerome-etienne/neoip
sudo apt-get update
sudo apt-get install nodejs

# install npm
curl http://npmjs.org/install.sh | sudo sh

# install lessjs
cd /opt
sudo npm install less
cd /usr/local/bin/
sudo ln -s /opt/node_modules/less/bin/lessc .
# use it!
# lessc [file]

# install csslint
sudo npm install -g csslint
# use it!
# csslint [file]

2019 Using Debian, as root

curl -sL https://deb.nodesource.com/setup_10.x | bash -
apt-get install -y nodejs
node -g install less