Start and stop gpuffs from Node.js.

$ npm install gpuffs

To use gpuffs.js, simply require it:

var gpuffs = require("gpuffs");

gpuffs' start method accepts a configuration object, which uses the same flags as the gpuffs command line client. (Here, the flags are organized into an object.) Flags that are not accompanied by a value on the command line (for example, --mine) should be passed in as { flag: null }.

var options = {
    networkid: "420",
    port: 31313,
    rpcport: 11363,
    mine: null
};

gpuffs.start(options, function (err, proc) {
    if (err) return console.error(err);
    // gpuffs active!!
});

The callback's parameter proc is the child process, which is also attached to the gpuffs object (gpuffs.proc) for your convenience.

When you are finished your session with gpuffs, stop kills the underlying gpuffs process:

gpuffs.stop(function () {
    // gpuffs stopped. 
});

The callback for start fires after gpuffs has successfully started. Specifically, it looks for "IPC service started" in gpuffs' stderr. If you want to change the start callback trigger to something else, this can be done by replacing gpuffs' default listeners. gpuffs.start accepts an optional second parameter which should specify the listeners to overwrite, for example:

{
    stdout: function (data) {
        process.stdout.write("I got a message!! " + data.toString());
    },
    stderr: function (data) {
        if (data.toString().indexOf("Protocol Versions") > -1) {
            gpuffs.trigger(null, gpuffs.proc);
        }
    },
    close: function (code) {
        console.log("Puff. Puff. PASS!!!!");
    }
}

In the above code, gpuffs.trigger is the callback passed to gpuffs.start. (This callback is stored so that the startup trigger can be changed if needed.) These three listeners (stdout, stderr, and close) are the only listeners which can be specified in this parameter, since only these three are set by default in geth.start.

If you want to swap out or add other listeners (after the initial startup), you can use the gpuffs.listen convenience method:

gpuffs.listen("stdout", "data", function (data) { process.stdout.write(data); });

This example (re-)sets the "data" listener on stdout by setting gpuffs.proc.stdout._events.data = function (data) { process.stdout.write(data); }.