javascriptv8

Running V8 Javascript Engine Standalone


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


Solution

  • 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:

    $> git clone https://chromium.googlesource.com/v8/v8
    ...
    $> 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:
    ...