Tanaka-Qtaro-Yasuhiro <tanaq@ca2.so-net.ne.jp> writes:

> 我が家にある Debian GNU/Linux 3.0 (Woody) で、
> $ cd //
> とやると、
> $ pwd
> //
> になります。

bash FAQ に次のようにあります。

| E10) Why does `cd //' leave $PWD as `//'?
| 
| POSIX.2, in its description of `cd', says that *three* or more leading
| slashes may be replaced with a single slash when canonicalizing the
| current working directory.
| 
| This is, I presume, for historical compatibility.  Certain versions of
| Unix, and early network file systems, used paths of the form
| //hostname/path to access `path' on server `hostname'.

-- 
Hiroshi Fujishima