Run command on file change

Tools from the inotify family allow to watch for events on file system.

For instance the inotifywait tool allows to be notified as soon as a file is modified.

You first need to install the tool

sudo pacman -S inotify-tool

And then you can watch for file changes. In this oneliner we re-run an executable file as soon as it has been recompiled:

while inotifywait -e close_write main; do sleep 1; ./main ; done