reverseGeo.js

var request = require('request');

var reverseGeocode = function(locationName, callback) {
    request({
        uri: "http://nominatim.openstreetmap.org/search?format=json&q="+locationName,
        json: true
    }, function(err, response, body) {
        if (err) { return callback(err, null); } 
        else {
            if (body && body.length) {
                return callback(null, body[0])
            } else {
                return callback("response is no array", null);
            }
        }
    });
}

var param = process.argv[2];

if (!param) {
    console.log('No parameter. Add location as parameter string (e.g. "Stuttgart, Germany")');
    process.exit();
}

reverseGeocode(param, function(err, data) {
    if (err) {
        console.log("Error: ", err);
        return;
    }

    var result = {importance: data.importance, type: data.type, lat: data.lat, lon: data.lon};

    console.log(result);
});