README

What?

Command line tool to create hard links to directories with Mac OS X (10.5 or later). This is used by Time Machine.

Credits:
http://www.mactech.com/articles/mactech/Vol.23/23.11/ExploringLeopardwithDTrace/index.html
http://osxbook.com/blog/2008/11/09/hfsdebug-40-and-new-hfs-features/

Restrictions:
The hard link must be created in a directory different from the source directory's parent. See example below.

How?

Compile:

  $ gcc -o hlink hlink.c -Wall

Link:

  ./hlink <source_dir> <target_dir>

Example:
  $ mkdir test1
  $ mkdir test2
  $ ./hlink test1 test2/test3

hlink.c

#include <unistd.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
   if (argc != 3)
      return 1;
   int ret = link(argv[1], argv[2]);
   if (ret != 0)
      perror("link");
   return ret;
}