How do I watch a file for changes?

Question

I have a log file being written by another process which I want to watch for changes. Each time a change occurs I\'d like to read the new data in to do some processing on it

Answer 1

Since I have it installed globally, my favorite approach is to use nodemon. If your source code is in src, and your entry point is src/app.py, then it's as easy as:

nodemon -w 'src/**' -e py,html --exec python src/app.py

... where -e py,html lets you control what file types to watch for changes.