sort.js

// Sort json by object keys

function sortObject(object){
    var sortedObj = {},
        keys = Object.keys(object);

    keys.sort(function(key1, key2){
        key1 = key1.toLowerCase(), key2 = key2.toLowerCase();
        if(key1 < key2) return -1;
        if(key1 > key2) return 1;
        return 0;
    });

    for(var index in keys){
        var key = keys[index];
        if(typeof object[key] == 'object' && !(object[key] instanceof Array)){
            sortedObj[key] = sortObject(object[key]);
        } else {
            sortedObj[key] = object[key];
        }
    }

    return sortedObj;
}

var fs = require('fs'),
    obj = JSON.parse(fs.readFileSync('input')),
    sobj = sortObject(obj);

setTimeout(function() {
  fs.writeFile('output', JSON.stringify(sobj, null, 2));
}, 10000);