Dnotify is a simple program based on linux kernel 2.4.19+'s dnotify api. dnotify can execute a specified command each time the content of a specific directory changes. it is run from the command line and takes two arguments: one or more directories to monitor and a command to execute whenever a directory has changed. options control what events to trigger on: when a file was read in the directory, when one was created, deleted and so on.