wav2mp3.js

//usage: $ node wav2mp3.js file1.wav file2.wav
// converts to .mp3 format and deletes original .wav file
// thanks to creationix for his assistance

var fs = require('fs');
var sys = require('sys');
var Step = require('step');
var spawn = require('child_process').spawn;
var exec = require('child_process').exec;
var counter = 0;


Step(
    function doConversions() {
	var group = this.group();
	process.argv.splice(2).forEach(function(arg){
	    convert(arg, group());
	    counter++;
	});
    },
    function printResults(){
	sys.puts("" + counter + " files converted to mp3");
    }
);

function convert(file, callback){
    if (file.slice(-4) === ".mp3"){
	sys.puts('file ' + file + ' already converted ');
    } else {
	
	Step(
	    function checkFile(){
		fs.stat(file, this);
	    },
	    function convertFile(err){
		if(err) {
		    sys.print(err.message)
		} else {
		    var conversion = exec('soundconverter -b -m ' + 
					  'audio/mpeg -s .mp3 ' + file, this);
		}
	    },
	    function deleteOriginal(err){
		if(err){
		    sys.print(err.message)
		} else {
		    exec('rm -f ' + file, this);
		}
	    },
	    callback
	);
    }
};