Entr is a unix utility that is simple to use, yet powerful tool for automation. It does not require any additional dependencies.
Main concept and function this tool delivers is enabling users to run arbitrary commands based on file changes. For example, if you wanted to perform certain commands or list of commands such as restarting a script of multiple scripts based on updates made to certain files, Entr will take care of that.
Tired of manually checking and repeating same commands over and over? Automate your command flow and let Entr take care of that for you.
For more details how it works please visit their website.