fswatch is a file change monitor that receives notifications when the contents 
of the specified files or directories are modified. fswatch implements four 
kinds of monitors:

  * A monitor based on the File System Events API of Apple OS X.
  * A monitor based on kqueue, an event notification interface introduced in 
    FreeBSD 4.1 and supported on most *BSD systems (including OS X).
  * A monitor based on inotify, a Linux kernel subsystem that reports file 
    system changes to applications.
  * A monitor which periodically stats the file system, saves file modification 
    times in memory and manually calculates file system changes, which can work 
    on any operating system where stat (2) can be used.

fswatch should build and work correctly on any system shipping either of the 
aforementioned APIs.

WWW: https://github.com/emcrisostomo/fswatch
