MonitorFile is a lightweight C++ header-only library for monitoring file changes in the filesystem. It provides an easy-to-use API to detect modifications to a file based on its last write time.
- Minimal dependencies – Uses standard C++20
<filesystem>. - Exception-safe – Handles missing or deleted files gracefully.
- Cross-platform – Works on Linux, macOS, and Windows (C++20 required).
MonitorFile/
│── src/ # Source files
│ ├── monitorfile.hpp # The header-only MonitorFile class
│ ├── main.cpp # Test program for monitoring file changes
│ ├── Makefile # Build system for testing
│── LICENSE.md # MIT License
│── README.md # Project documentation
To test the functionality, clone the repository and compile the test program:
git clone https://github.com/WsprryPi/MonitorFile.git
cd MonitorFile/src
make testInclude the Library
#include "monitorfile.hpp"Basic Example
#include "monitorfile.hpp"
#include <iostream>
#include <fstream>
#include <thread>
#include <chrono>
int main()
{
MonitorFile monitor;
const std::string testFile = "testfile.txt";
// Create a test file
{
std::ofstream file(testFile);
file << "Initial content.\n";
}
// Start monitoring
try
{
monitor.filemon(testFile);
}
catch (const std::exception &e)
{
std::cerr << "Error: " << e.what() << std::endl;
return 1;
}
std::cout << "Monitoring file: " << testFile << "\n";
for (int i = 0; i < 5; ++i)
{
std::this_thread::sleep_for(std::chrono::seconds(3));
// Modify the file
if (i % 2 == 1)
{
std::ofstream file(testFile, std::ios::app);
file << "Modification " << i << "\n";
}
try
{
if (monitor.changed())
{
std::cout << "File has been modified!\n";
}
else
{
std::cout << "No changes detected.\n";
}
}
catch (const std::exception &e)
{
std::cerr << "Error: " << e.what() << std::endl;
break;
}
}
return 0;
}To compile and run the test program:
make testTo clean up compiled files:
make cleanTo run static analysis (requires cppcheck):
make lintMonitorFile throws std::runtime_error in these cases:
- The file does not exist when calling
filemon(). - The file is deleted while monitoring.
To prevent crashes, always wrap calls to filemon() and changed() in a try-catch block.
This project is licensed under the MIT License. See LICENSE.md for details.
Pull requests and feature suggestions are welcome.
To contribute:
- Fork the repository.
- Create a feature branch (git checkout -b feature-name).
- Commit your changes (git commit -m "Add new feature").
- Push to the branch (git push origin feature-name).
- Open a Pull Request.
- For issues, please open an Issue.
- For questions, reach out to Lee C. Bussy (@LBussy).