PBLOCK - Content Blocker

A self-accountability content blocking tool that prevents access to adult websites by modifying the system hosts file. Available for Linux, Windows, and Android.

Project Structure

PBLOCK/
├── README.md
├── .gitignore
│
├── LinuxVersion/
│   └── mainPBLOCK.cpp           # Linux CLI tool (C++)
│
├── WindowsVersion/
│   └── mainPBLOCK.cpp           # Windows CLI tool (C++)
│
├── AndroidVersion/              # Android app (Java + C++ JNI)
│   ├── build.gradle
│   ├── settings.gradle
│   ├── gradle.properties
│   ├── setup.sh
│   ├── app/
│   │   ├── build.gradle
│   │   └── src/main/
│   │       ├── AndroidManifest.xml
│   │       ├── cpp/
│   │       │   ├── CMakeLists.txt
│   │       │   └── mainPBLOCK.cpp       # Native JNI code
│   │       ├── java/com/pblock/app/
│   │       │   └── MainActivity.java    # Android UI + logic
│   │       └── res/
│   │           ├── layout/activity_main.xml
│   │           └── values/
│   │               ├── strings.xml
│   │               └── colors.xml
│   └── gradle/wrapper/
│
└── scripts/                     # NSFW blocking scripts (no root needed)
    ├── README.md                # Detailed usage instructions
    ├── nsfw_hosts.txt           # Hosts file with 200+ blocked domains
    ├── block_nsfw_adb.sh        # ADB-based hosts file push script
    └── setup_private_dns.sh     # Private DNS setup (Android 9+, no root)

How It Works

1. Set a password - You create a strong password (min 8 characters) that will be required to disable blocking
2. Enable blocking - The tool adds entries to your system's hosts file, redirecting blocked domains to 127.0.0.1
3. Intentional delay - When you try to disable blocking, there is a mandatory 30-second wait period to help you reconsider
4. Password required - After the delay, you must enter your password to remove the blocks

The hosts file entries are wrapped with # CONTENT_BLOCKER_START and # CONTENT_BLOCKER_END markers for clean insertion and removal.

Features

• System-level domain blocking via hosts file modification
• Password-protected unblocking with SHA-256 hashing
• 30-second intentional delay before unblocking (time to reconsider)
• Status display showing active/inactive state and domain count
• Cross-platform: Linux, Windows, and Android
• NSFW blocking scripts for non-rooted Android phones (no root needed!)

Android NSFW Blocking (No Root Required)

Don't have a rooted phone? Use the scripts in the scripts/ folder to block NSFW content without root access.

Quick Start: Private DNS (Easiest Method)

Set this up directly on your phone — no computer needed:

1. Open Settings → Network & Internet → Private DNS
2. Select Private DNS provider hostname
3. Enter: family-filter-dns.cleanbrowsing.org
4. Tap Save

All adult content is now blocked on every app and browser. See scripts/README.md for more options.

Other Methods

Method	Root	Computer	Details
Private DNS	No	No	Set a family-safe DNS on your phone. Guide
ADB Hosts File	No	Yes	Push a blocking hosts file via USB. Guide
PBLOCK App	Yes	No	Full app with password protection. See below.

Technology Stack

• C++17 - Core blocking logic (all platforms)
• JNI (Java Native Interface) - Android native integration
• Java - Android app UI and system interaction
• Android SDK 35 - Android build target
• CMake 3.22 - Native build system for Android
• Gradle 8.x - Android build tool

Prerequisites

Linux

• g++ with C++17 support
• Root/sudo access (required to modify /etc/hosts)

Windows

• MSVC or MinGW with C++17 support
• Administrator privileges (required to modify the hosts file)

Android (App - requires root)

• Android Studio or Android SDK
• NDK (for native C++ compilation)
• Rooted device (required to modify /system/etc/hosts)

Android (Scripts - no root required)

• Android 9+ for Private DNS method (no other requirements)
• ADB for hosts file method (requires a computer with USB cable)

Build & Run

Linux

cd LinuxVersion
g++ -std=c++17 -o blocker mainPBLOCK.cpp -lcrypt -lpthread
sudo ./blocker setup    # Set password
sudo ./blocker block    # Enable blocking
sudo ./blocker unblock  # Disable blocking (requires password + 30s delay)
sudo ./blocker status   # Show current status

Windows

Compile WindowsVersion/mainPBLOCK.cpp with MSVC or MinGW (requires linking against advapi32):

cl /EHsc /std:c++17 mainPBLOCK.cpp /link advapi32.lib
# Run as Administrator:
blocker.exe setup
blocker.exe block
blocker.exe unblock
blocker.exe status

Android (App)

cd AndroidVersion
# Set your Android SDK path in local.properties
# Then build with Gradle:
chmod +x gradlew
./gradlew assembleDebug
# Or open the project in Android Studio

The APK will be generated at AndroidVersion/app/build/outputs/apk/debug/app-debug.apk.

To install on your phone:

1. Transfer the APK to your phone
2. Open it and tap Install (you may need to enable "Install from unknown sources")
3. Open PBLOCK and follow the on-screen instructions

Android (Scripts - No Root)

cd scripts/

# Option 1: Set up Private DNS (recommended, Android 9+)
chmod +x setup_private_dns.sh
./setup_private_dns.sh

# Option 2: Push hosts file via ADB
chmod +x block_nsfw_adb.sh
./block_nsfw_adb.sh

See scripts/README.md for detailed instructions.

Security Notes

1. Run with appropriate privileges - Linux requires sudo, Windows requires Administrator, Android requires root (for the app)
2. Use a strong password - Minimum 8 characters, write it down somewhere safe
3. The 30-second delay is intentional - It gives you time to reconsider before unblocking
4. Hosts file modification - This app modifies system files; back up your hosts file before first use
5. Private DNS is the safest method for non-rooted Android phones — it blocks content at the DNS level across all apps

Contributing

Contributions are welcome. If you find security vulnerabilities, please report them responsibly.

License

MIT License

Support

For issues or questions:

• Open an issue on GitHub
• Email: modistotube2004@gmail.com