SaneCppFileSystemWatcher.h is a library that allows watching directories for changes that happen to them.

Dependencies

• Dependencies: (none)
• All dependencies: (none)

Features

• Get notified about modified files or directories
• Get notified about added / removed / renamed files or directories
• Async backend support via FileSystemWatcherAsyncT template

Status

Usable Library does have basic capabilities and it can be used just fine.

Blog

Some relevant blog posts are:

• June 2025 Update
• July 2025 Update
• March 2026 Update

Description

Videos

This is the list of videos that have been recorded showing some of the internal thoughts that have been going into this library:

• Ep.09 - SC::FileSystemWatcher Linux inotify implementation

Blog

Some relevant blog posts are:

• June 2024 Update

Details

The class tries to unify differences between OS specific API to deliver folder change notifications

• On macOS and iOS FSEvents by CoreServices is used.
• On Windows ReadDirectoryChangesW is used.

The behavior between these different system also depends on the file system where the watched directory resides.

Note: On iOS FSEvents api is private so using SC::FileSystemWatcher will be very likely causing your app to be rejected from the app store.

Examples

• SCExample uses SC::FileSystemWatcher for a simple hot-reload system
• Tests inside FileSystemWatcherTest.cpp show how the API is meant to be used
• Tests inside FileSystemWatcherAsyncTest.cpp show how the Async API is meant to be used

Roadmap

Complete Features:

• Not sure what else could be useful here

💡 Unplanned Features:

• Having a thread based polling stat watcher that checks file modifications on intervals as fallback
• Allow users to provide their own thread instead of creating it behind the scenes

Statistics

LOC counts exclude comments. Library counts files physically under Libraries/FileSystemWatcher. Single File counts SaneCppFileSystemWatcher.h. Standalone counts SaneCppFileSystemWatcherStandalone.h and intentionally includes dependency payloads.