sysadmin

Walk a Directory in Python

A common task when working with files is to walk through a directory, that is, recursively get every file in every directory starting in some location. The Python 3 os module has several functions useful for working with files and directories. One in particular, os.walk() is useful for recursively going through a directory and getting the contents in a structured way. These examples will show you a couple options for walking a directory recursively.

Get Password in Console with Ruby

In Ruby 2.3, they introduced a getpass method on the IO::console class. There are no dependencies since it part of the standard library, but it's only available in versions higher than 2.3. For older versions, we'll look at an alternative method. The getpass method is similar to gets except it will not echo back what you are typing in. This is good for getting a password without printint it to the screen when you type it in. This will demonstrate how to use the method. See the official documentation for IO::console#getpass for more details. We will also look using $stdin.noecho() to wrap Kernel.gets to get a password.

GPG Tutorial

GnuPG is a cryptography tool that helps you manage public and private keys as well as perform encrypt, decrypt, sign, and verify operations. It is an open-source version of PGP. This tutorial will go over basic key management, encrypting (symmetrically and asymmetrically), decrypting, signing messages, and verifying signatures with GPG.

Create ASCII Art Text Banners in Python

ASCII art has a long history in the hacker culture. If you check out any Phrack article and there is almost guaranteed to be some form of ASCII art in there. In this example we are specifically talking about ASCII art fonts that can be used to make banner text for command-line applications, network services, documentation, web pages, etc.

Nginx Tutorial

Nginx, pronounced "engine X", is a fast and lightweight web server, that can be used to serve static files, but is often used as a reverse proxy. It has some very nice features like load balancing and rate limiting. We'll cover some common use cases like serving files, creating a directory listing, reverse proxying to pass incoming traffic to a local web server, adding SSL encryption, and how to require https and www on your site. This guide is for someone who needs a quick reference to setting up a simple nginx server. For the latest documentation always check out the official website https://www.nginx.com/ and the source mirror at https://github.com/nginx/nginx.

One-line HTTP servers

If you need a quick-and-dirty HTTP server that doesn't need fancy configuration, try some of these one-line HTTP servers in languages like Python, Ruby, and PHP. Some examples include a small script that allows you to embed the server in to your program and add more customization. These are not intended for production use.