hBlock is a POSIX-compliant shell script that downloads multiple ad, tracking, and malware domain blocklists from curated sources, processes them into a unified hosts file (or alternative formats like dnsmasq, unbound, adblock, Windows PowerShell), and installs it to block those domains at the system level. The core architecture is a single self-contained script (hblock) with a custom option parser, robust error handling, and support for parallel downloads, allow/deny lists, template-based output formatting, and subdomain filtering. It is not a reusable library but a complete CLI tool; however, its companion scripts (resource/alt-formats/*.sh) demonstrate a clean plugin pattern for generating multiple output formats, and the stats script (resources/stats/stats.sh) provides a reusable utility for analyzing domain lists against the Public Suffix List. The project is well-maintained, tested across multiple shells and platforms, and follows strict POSIX shell practices.
Pi-hole is a network-wide ad blocking application that operates as a DNS sinkhole. The repository contains the core shell scripts for installation, configuration, and management of the Pi-hole system. The primary entry points are the `pihole` CLI command and `gravity.sh`, which downloads and compiles blocklists into a SQLite database. The architecture is a collection of bash scripts that orchestrate the FTLDNS daemon (a separate binary) and provide a command-line interface for allow/deny lists, querying, debugging, and updates. The code is well-structured with modular functions, error handling, and extensive test coverage across multiple Linux distributions. It is a mature, actively maintained project with a large community.
This repository is a data pipeline that aggregates and consolidates hosts files from 20+ upstream sources (adaway.org, mvps.org, someonewhocares.org, yoyo.org, URLHaus, KADhosts, hostsVN, and others) into unified blocklists for adware, malware, tracking, and optional categories (porn, gambling, fake news, social media). The core pipeline (`updateHostsFile.py`) fetches remote hosts files via HTTP, parses them, deduplicates entries, applies whitelist/blacklist filters, and generates a primary `hosts` file plus 30+ alternate permutations in `alternates/`. Each source has metadata in `update.json` (URL, license, frequency). The `makeHosts.py` script orchestrates full matrix generation of all extension combinations. Output includes stats tracking (`stats.out`, `stats.png`) and auto-generated READMEs via `updateReadme.py`. The repo includes Docker support, GitHub Actions CI (lint, test, multi-Python), CodeQL scanning, and automated dependency updates via Dependabot. Data sources are external URLs; the pipeline is idempotent and designed for scheduled runs.
AdAway is an open-source Android ad-blocking application that provides two methods for blocking ads: modifying the system hosts file (requires root) and a local VPN-based DNS filter. The app downloads and manages multiple hosts sources from URLs, parses them into a local Room database, and applies the blocklists either by writing to /etc/hosts or by intercepting DNS queries through a local VPN service. The VPN mode maps real DNS servers to fake addresses, forwards allowed queries, and returns blocked or redirected responses. The architecture follows MVVM with LiveData, ViewModel, and Room, and includes background workers for periodic updates. The app bundles a legacy native C library (tcpdump/libpcap) for packet capture, used for DNS logging. The codebase is actively maintained, with frequent commits and releases, but some native components are outdated and the VPN implementation may have compatibility issues on newer Android versions.