雖然常常用 lsof 不過之前都不知道有這招
A deleted file has zero links. So the following command displays deleted-but-open files on a system.
$ lsof +L1
Display a list of deleted-but-open files within a specific filesystem.
$ lsof +aL1 /tmp
From http://0xfe.blogspot.com/2006/03/troubleshooting-unix-systems-with-lsof.html
