fswatch command

# To run a bash command on file creation, update or deletion:
fswatch <path/to/file> | xargs -n 1 <bash_command>

# To watch one or more files and/or directories:
fswatch <path/to/file> <path/to/directory> <path/to/another_directory/**/*.js> | xargs -n 1 <bash_command>

# To print the absolute paths of the changed files:
fswatch <path/to/directory> | xargs -n 1 -I {} echo {}

# To filter by event type, eg. Updated, Deleted or Created:
fswatch --event <Updated> <path/to/directory> | xargs -n 1 <bash_command>