Strange behaviour of the "cd" command

[Dr Rainer Woitok]

Joel,

On Tuesday, 2017-07-11 10:51:53 +0900, you wrote:

> ...
> > $ echo $SHELL
> > /usr/bin/ksh
> > $ unset CDPATH
> > $ ls -la / | head -4
> > total 116
> > drwxr-xr-x  24 root root  4096 2017-06-26 19:05 .
> > drwxr-xr-x  24 root root  4096 2017-06-26 19:05 ..
> > drwx------   2 root root  4096 2016-05-25 11:19 .cache
> > $ cd /.cache
> > /usr/bin/ksh: hist[7]: cd: /.cache: [Permission denied]
> ...
> Having a /.cache might indicate that something succeeded half-way
> at su-ing to root without enough permission to read root's login directory,
> or something like that.

You might well be right.  But for the case at hand it doesn't matter.  I
just used this directory as a guinea pig to demonstrate the problem.

> ...
> I made a /.cache directory, just for grins, but I don't reproduce this. My
> shell is bash.

But as one can see from the output of "echo $SHELL" above, I used a Korn
Shell.  And since the "cd" command is a shell built-in, I'm not surpris-
ed you can't reproduce the problem using a Bash Shell.

> ...
> Check whether you have an executable called "cd" somewhere in
> your PATH. (You shouldn't, of course.)

I haven't, of course.  But you're right, I should have added the command
"whence cd" to the problem description.

Sincerely,
  Rainer