hex-dump: A Hex Viewer and File Type Finder

A fast, modern command-line tool for viewing file contents in hexadecimal and identifying file types using magic number signatures.

hex-dump is a C++ application for developers, reverse engineers, and digital forensics analysts who need a quick way to inspect file internals and determine a file's true type, regardless of its extension.

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Table of Contents

• About The Project
• Features
• Getting Started
  • Prerequisites
  • Building
• Usage

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About The Project

This tool serves two primary purposes: a hex viewer and a file type finder.

As a hex viewer, it provides a clean, formatted hexadecimal and ASCII representation of a file's contents.

As a file type finder, it reads a file's raw byte content and searches for known "magic number" signatures that identify its true type. For example, it can identify a PNG image even if it's been renamed with a .txt extension.

Efficiency is a core design goal. hex-dump uses memory-mapped I/O (mmap) to handle large files with minimal overhead and the Aho-Corasick algorithm to search for all known file signatures in a single, efficient pass.

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Features

• Dual Functionality: Acts as both a hex viewer and a file type finder.
• High-speed Scanning: Utilizes memory-mapped files to minimize I/O overhead.
• Efficient Multi-pattern Search: Employs the Aho-Corasick algorithm to find all known signatures in one pass.
• Cross-Platform: Built with standard C++ and CMake, targeting POSIX-compliant systems (Linux, macOS).

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Getting Started

Follow these instructions to get a copy of the project up and running on your local machine.

Prerequisites

• C++20 Compliant Compiler:
  • GCC 10 or newer
  • Clang 12 or newer
• CMake:
  • Version 3.10 or newer
• Git

Building

1. Clone the repository

   git clone https://github.com/your_username/hex-dump.git
   cd hex-dump

2. Create a build directory and configure

   mkdir build && cd build
   cmake ..

3. Compile the project

   make

The compiled binary, hex-dump, will be located in the build directory.

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Usage

Run the tool from the command line, passing the path of the file you wish to inspect as an argument.

./build/hex-dump /path/to/your/file.ext

Example Output

[+] Hexdump of the first 100 bytes:
00000000: 89 50 4e 47 0d 0a 1a 0a 00 00 00 0d 49 48 44 52  |.PNG........IHDR|
00000010: 00 00 01 f4 00 00 01 f4 08 06 00 00 00 1f 15 c4  |................|
...

[+] Matches found: 1
  Offset: 0x0 | Pattern: 89 50 4e 47 0d 0a 1a 0a | File type: png