OS X: Deleted files still accessible through Terminal session?

Question

This is something neat that I've discovered today- I was modifying gcov files in a terminal. I had one window open with old gcov files from 11 AM. At 11:15, I ran my program again, and recreated the gcov files (overwriting the old ones). I looked at them in a second terminal window. However, I discovered I could still view the 11 AM gcov files in the first window!

Is this because of how the OS X file system works, that deleted files are still somewhat accessible? It seems to be connected to how one can rename or move files that are already open, unlike in Windows.

Answer 1

A directory entry points to an inode, the inode contains metainfo and points to the file data. You can remove the directory entry (this reduces the reference count of the inode), or close the open file (also reduces the reference count of the inode). When the inode reference count is 0, then the actual file is deleted.

On e.g. FAT filesystems, the "inode" and the directory entry are the same entity - so removing a directory entry also removes the file.