README.md

NodeJS Secure File Removal Utility

Use Node JS to securely delete files on your server with Unix's shred command. You really don't need this module if the machine your running your project on is not using a tranditional mechanical hard drive. In other words, if the file you want to securely delete is on solid state storage, there's no need to use this module and, in fact, it could actually be unnecessarily shortening the life of that disk to use it.

NOTE: This module is not designed to work on Windows but may work on WSL. Your mileage may vary.

How to Install

With NPM:

npm install shredfile

With Yarn:

yarn add shredfile

License info

Licensed under the MIT License:

• http://www.opensource.org/licenses/mit-license.php

Getting Started

All of the values listed in the example below represent the default values for their respective configuration item.

You can simply do this:

const ShredFile = require('shredfile');
const shredder = new ShredFile();

And, you'll be good to go.

BUT: If you want more control, you can specify all sorts of options.

const ShredFile = require('shredfile');
const shredder = new ShredFile({
    shredPath: '/usr/bin/shred', // Path to shred binary on your server
    force: false, // If true, changes permissions of the file(s) to allow writing if necessary
    iterations: 3, // How many times to overwrite the file
    bytes: null, // If specified, it will shred to specified bytes and then stop
    remove: true, // If true, removes (unlinks) file(s) after shredding
    zero: true, // If true, adds final overwrite with zeros to hide shredding
    debugMode: false // Whether or not to log info/debug/error msgs to the console
});

Here is a non-default values example (to help you get an idea of what some proper-looking alternate values could be):

const ShredFile = require('shredfile');
const shredder = new ShredFile({
    shredPath: '/usr/local/bin/shred', // Maybe yours is located here
    force: true, // You do want to change permissions to force writing
    iterations: 25, // You wear a tinfoil hat at all times, so, naturally, write over the file 25 times.
    bytes: '70M', // You're shredding the first 70 MB of the file only.
    remove: false, // You want to shred the file but keep it there for some reason.
    zero: false, // You don't care about hiding the fact that you shredded the file.
    debugMode: true // You want to know everything that happened.
});

API

.shred(files, statusCb, endCb)

This method allows you to shred a one or many files.

Parameters

• files required (string or array) A path (string) or list paths (array) to file(s) you want to be shredded.
• statusCb (function) Will be called everytime the status of a file is changed (ex. renaming and each overwrite iteration). It takes 4 parameters:
  • action (string) This will be either 'overwriting' or 'renaming'
  • progress (float) The percentage of the specific action that is complete (ex. 0.66)
  • file (string) File name of the file that is currently being acted upon
  • activeFilePath (string) Full path to the file that is currently being acted upon (does not include file name)
• endCb (function) Will be called when the shred is complete. It takes 2 parameters:
  • err (string or null) A standard error message string (null if no error)
  • file (string) The original files parameter passed into this shred method.

Examples

Single File (Callback Style)

shredder.shred('/a/picture/for_example.jpg', (err, file) => {
    if (err) return console.error(err);
    console.log("File has been shredded!");
});

Single File (Async/Await)

async function doShred() {
    try {
        const file = await shredder.shred('/a/picture/for_example.jpg');
        console.log('Shredded File: ', file);
    } catch (err) [
        console.error(err);
    }
}

doShred();

Multiple Files (with status callback) - Callback Style

const files = ['/a/picture/for_example.jpg','/a/different/file.dat'];
shredder.shred(files, (action, progress, file, path) => {
    progress = (Math.round((progress * 10000)) / 100);
    console.log(`${action} ${file}: ${progress}%`);
}, (err, file) => {
    if (err) return console.error(err);
    console.log("Files have been shredded!");
});

Multiple Files (with status callback) - Promise Style

const files = ['/a/picture/for_example.jpg','/a/different/file.dat'];
shredder.shred(files, (action, progress, file, path) => {
    progress = (Math.round((progress * 10000)) / 100);
    console.log(`${action} ${path}/${file}: ${progress}%`);
}).then((files) => {
    console.log('Files have been shredded!', files);
}).catch((err) => {
    console.error(err);
});