watch-files is a basic file system watcher to execute a command upon file changes.
To install the binary, run:
cargo install watch-files  <files> | watch-files "<command>"
  <files> | watch-files [-p <poll_time_in_ms>] "<command>"
  watch-files -h|--help
The following will watch all files in the src directory, and run cargo build when a file changes.
find src/* | watch-files "cargo build"The following will watch all files in the src directory every 1000 milliseconds, and run cargo build when a file change is detected.
find src/* | watch-files --poll-rate 1000 "cargo build"The following will print the help text
watch-files --help