Commit c05936c

`vm.runInContext` compiles `code` to run in context `context` as if it were loaded from `filename`,

then runs it and returns the result. A (V8) context comprises a global object, together with a

set of built-in objects and functions. Running code does not have access to local scope and

the global object held within `context` will be used as the global object for `code`.

`filename` is optional.

Example: compile and execute code in a existing context.

var util = require('util'),

vm = require('vm'),

initSandbox = {

animal: 'cat',

count: 2

},

context = vm.createContext(initSandbox);

vm.runInContext('count += 1; name = "CATT"', context, 'myfile.vm');

console.log(util.inspect(context));

// { animal: 'cat', count: 3, name: 'CATT' }

Note that `createContext` will perform a shallow clone of the supplied sandbox object in order to

initialise the global object of the freshly constructed context.

Note that running untrusted code is a tricky business requiring great care. To prevent accidental

global variable leakage, `vm.runInContext` is quite useful, but safely running untrusted code

requires a separate process.

In case of syntax error in `code`, `vm.runInContext` emits the syntax error to stderr

and throws an exception.

`vm.createContext` creates a new context which is suitable for use as the 2nd argument of a subsequent

call to `vm.runInContext`. A (V8) context comprises a global object together with a set of

build-in objects and functions. The optional argument `initSandbox` will be shallow-copied

to seed the initial contents of the global object used by the context.