File Monitor

File Monitor is a command‑line utility that interfaces directly with the macOS and iOS FSEvents API to observe filesystem activity. It can log events such as file creation, modification, and deletion, and it offers optional actions that are triggered automatically when a matching event occurs. The “stop” action sends a SIGSTOP to the originating process, allowing a developer to attach a debugger, while the “link” action creates a hard‑link to a newly created file to keep its inode alive and prevent immediate removal.

The tool supports filtering by pathname patterns, process names or IDs, and specific event types, which helps limit its scope and avoid unintended side effects when using automatic actions. Filters are supplied as comma‑separated lists via command‑line options. Colorized output can be enabled for easier reading, and the program excludes its own events from the stream.

File Monitor is intended for developers and system administrators who need to monitor and intervene in file system operations on macOS or iOS, particularly for debugging or for preserving files that would otherwise be deleted. It is a stable, freeware utility that runs on those platforms without requiring additional dependencies.