Incron
incron is an “inotify cron” system. It consists of a daemon and a table manipulator. You can use it a similar way as the regular cron. The difference is that the inotify cron handles filesystem events rather than time periods.
I use it to auto-commit changes made to specific files to version control.
Example usage
View incrontabs:
Add/edit incrontabs:
Archwiki for more info.