This is a small program using the events a directory.
When an event about any change to that directory is received, the specified
shell command is executed by /bin/bash.
fswatch of notifytools use version.
required cmake.
% mkdir build && cd build
% cmake ..
% make
% make install
% fswatch /some/dir "echo changed"
This would monitor /some/dir for any change, and run echo changed
when a modification event is received.
In the case you want to watch multiple directories, just separate them with colons like:
% fswatch /some/dir:/some/otherdir "echo changed"