// Use as a module
npm install node-wifi

// Use as a CLI
npm install node-wifi -g

var wifi = require('node-wifi');

// Initialize wifi module
// Absolutely necessary even to set interface to null
wifi.init({
    iface : null // network interface, choose a random wifi interface if set to null
});

// Scan networks
wifi.scan(function(err, networks) {
    if (err) {
        console.log(err);
    } else {
        console.log(networks);
        /*
        networks = [
            {
                ssid: '...',
                mac: '...',
                frequency: <number>, // in MHz
                signal_level: <number>, // in dB
                security: '...' // unfortunately the format still depends of the OS
            },
            ...
        ];
        */
    }
});

// Connect to a network
wifi.connect({ ssid : "ssid", password : "password"}, function(err) {
    if (err) {
        console.log(err);
    }
    console.log('Connected');
});

// Disconnect from a network
// not available on all os for now
wifi.disconnect(function(err) {
    if (err) {
        console.log(err);
    }
    console.log('Disconnected');
});

// Disconnect from a network
// not available on all os for now
wifi.getCurrentConnections(function(err, currentConnections) {
    if (err) {
        console.log(err);
    }
    console.log(currentConnections);
    /*
    // you may have several connections
    [
        {
            iface: '...', // network interface used for the connection, not available on macOS
            ssid: '...',
            mac: '...',
            frequency: <number>, // in MHz
            signal_level: <number>, // in dB
            security: '...' // not available on linux
        }
    ]
    */
});

wifi --scan

wifi --connect --ssid <ssid> --password <password> [--iface <wlan0>]

wifi --disconnect

wifi --current