var os = require("os");

var os_func_list = Object.keys(os);

os_func_list.forEach(function(element) {

    // I know this is not working
    // var func = "os." + element + "()";
    // console.log(func);
}, this);

var os = require("os");

var os_func_list = Object.keys(os);

os_func_list.forEach(function(element) {
  var func = os[element];
  func()
});

os_func_list.forEach(function(element) {
    os[element](/*...args here if desired...*/);
}, this);

os_func_list.forEach(function(element) {
    os[element].call(/*...this argument here...*/, /*...args here if desired...*/);
}, this);