I had a need to batch edit a bunch of json files I had scraped containg my user information, each in a seperate file. There was going to be a mass update of the system so this way I could get a before and after.

Certain attributes in the export of each user will have changed in every item, and they were not relevant so when doing a bulk comparison using code compare these would show up so had to be removed.

My files were all named out.guidofuser.json and stored in folders by group so I needed to edit all of them, remove the attributes, beautify them else viewing the comparison would be hard if there was a difference.

NodeJS is wonderful at doing this stuff.

a quick npm init and npm install fs, path then this code, ripped through all my json files, edited and beautified them.

var fs = require("fs");
var path = path || require('path');

var walkSync = function (dir, filelist) {

    files = fs.readdirSync(dir);
    filelist = filelist || [];
    files.forEach(function (file) {
        if (fs.statSync(path.join(dir, file)).isDirectory()) {
            filelist = walkSync(path.join(dir, file), filelist);
        } else {
            var fPath = path.join(dir, file);
            var jsFile = require(fPath);

            for (var g in jsFile.groups) {
                delete jsFile.groups[g].modified;
                delete jsFile.groups[g].created;
            delete jsFile.lastLogin;
            delete jsFile.loginCount;

            var json = JSON.stringify(jsFile, null, 4);
            fs.writeFileSync(fPath, json);

    return filelist;

var fl = walkSync("C:\\Users\\simon\\stg2", []);