rakyll/fsnotify

fsnotify is a tool for programmers building applications in the Go language. It lets your software automatically notice the moment a file or folder is created, modified, deleted, or renamed, without having to constantly check for changes manually. This is especially useful for apps like file synchronizers or code tools that need to react instantly when something on the computer's disk changes. In technical terms, the library provides a "watcher" that you point at a specific file path. Once the watcher is running, it sends a message to your application every time a relevant action happens to that path. For each event, your app receives the name of the file and exactly what happened to it, allowing your program to trigger a specific response immediately after the event occurs. A developer building a desktop backup tool, for instance, could use this to instantly flag a document for upload the second a user saves it. Or a web server might use it to automatically reload its configuration files the moment an administrator makes an edit. The library is designed to work seamlessly across Windows, macOS, and Linux, which means a developer can write the file-watching logic once and trust it will run reliably on any of those operating systems. The project makes a few notable choices that developers should be aware of. Watching a folder does not automatically mean it watches the subfolders inside it, developers have to set up watchers for each specific directory they care about. Additionally, the current setup requires the developer to manage background processes to listen for the file events and potential errors, though the project notes it is looking into a simpler approach.