index.js

#! /usr/bin/env node
var
    https = require('https'),
    os = require('os');


function exit() {
    process.stdout.write('Bye!' + os.EOL);
    process.exit();
}

process.stdin.resume();
process.on('SIGINT', exit);


function explain(cmd, callback) {
    https.get('https://www.mankier.com/api/v2/explain/?cols=' + process.stdout.columns + '&q=' + encodeURIComponent(cmd), function (res) {
        res.on('data', function (d) {
            process.stdout.write(d);
        });
        res.on('end', function () {
            callback();
        });
    }).on('error', function (e) {
        console.log('Got error: ' + e.message);
    });
}

if (process.argv.length === 2) {

    process.stdout.write('Command: ');

    process.stdin.resume();
    process.stdin.setEncoding('utf8');

    process.stdin.on('data', function (text) {
        var cmd = text.trim();
        if (cmd === '' || cmd === 'quit') {
            exit();
        } else {
            explain(cmd, function () {
                process.stdout.write('Command: ');
            });
        }
    });

} else {

    var myArgs = process.argv.slice(2);
    explain(myArgs.join(' '), function () {
        process.exit();
    });

}