Running V8 Javascript Engine Standalone

Question

I want to run a Javascript console on top of V8. How do I do this?

Answer 1

V8 is easy to build and does not come with the Java VM overhead from Mozilla's standalone Javascript interpreter. Luckily, V8 ships with code for building a console. Here is how to build this:

$> svn co http://v8.googlecode.com/svn/trunk v8-trunk
...
$> cd v8-trunk
$> scons
$> g++ ./samples/shell.cc -o v8-shell -I include libv8.a 

Now, we have a standalone binary called v8-shell.

Running the console:

$> ./v8-shell 
V8 version 2.0.2
> var x = 10;
> x
10
> function foo(x) { return x * x; }
> foo
function foo(x) { return x * x; }
> quit()

Executing Javascript from the command line:

$> ./v8-shell -e 'print("10*10 = " + 10*10)'
10*10 = 100

Many more features are documented in the help:

$> ./v8-shell --help
Usage:
...