Do not optimize by assuming that directories contain 2 fewer subdirectories than their hard link count.  This option is needed  when  searching filesystems  that do not follow the Unix directory-link convention, such as CD-ROM or MS-DOS file systems or AFS volume mount points.  Each direc‐ tory on a normal Unix filesystem has at least 2 hard links: its name a its ‘.’  entry.  Additionally, its subdirectories (if any) each  have  a ‘..’  entry  linked to that directory.  When find is examining a directory, after it has statted 2 fewer subdirectories than  the  directory’link  count,  it knows that the rest of the entries in the directory arenon-directories (‘leaf’ files in  the  directory  tree).  If  only  the files’  names  need  to be examined, there is no need to stat them; this gives a significant increase in search speed

1 Do not optimize by assuming that directories contain 2 fewer subdirectories than their hard link count

这句话什么意思？ 
2 it has statted 2 fewer subdirectories than  the  directory’link  count

   stat这里指什么?，还有2 fewer

   谢谢!

不要优化文件夹，如果这个文件夹包含的子文件夹数只比该文件夹的硬链接数多2个或者少于2个。

1. 不進行優化, 假設每個目錄有(hard link 數出來少兩個) 的子目錄

2. stat 是一個 function
http://www.opengroup.org/onlinepubs/000095399/functions/stat.html

stat是取得文件状态的意思