Java DTrace bridge on OS X

Question

I am trying to grab filesystem events on OS / Kernel level on OS X. There are 2 requirements i have to follow. The first one is to do this in java as the whole project im developing for is written in java. The second one is that i have to find out when a document is opened.

For Linux I used inotify-java, but I can't find a good equivalent on OS X. Also the JNA doesn't provide a helpful binding. Currently I'm avoiding catching events by frequently calling the lsof program. This, however, is a bad solution.

Thanks for the help.

score 1 · Answer 1 · answered Jul 11 '11 at 19:10

You can use dtrace on OSX, but since it needs root privileges it's not something you'd want to put into a runtime of a system.

In any case, you won't be able to do this in pure Java (any Java API would be a wrapper around some lower level C introspection, and if you're doing it kernel-wide, would need to be done as root).

If you just want to track when your program is opening files (as opposed to other files on the same system) then you can install your own Security Manager and implement the checkRead() family of methods, which should give you an idea of when accesses are happening.

import java.io.*;

public class Demo {
  public static void main(String args[]) throws Exception {
    System.setSecurityManager(new Sniffer());
    File f = new File("/tmp/file");
    new FileInputStream(f);
  }
}
class Sniffer extends SecurityManager {
  public void checkRead(String name) {
    System.out.println("Opening " + name);
  }
}

Java DTrace bridge on OS X

1 Answers1