Re: Mounting DVD. What am I doing wrong?

[Rick Thomas <rbthomas@pobox.com>]

On May 1, 2010, at 3:25 PM, Camaleón wrote:

> On Sat, 01 May 2010 14:08:21 -0500, Ron Johnson wrote:
>
> > On 05/01/2010 02:03 PM, Camaleón wrote:
>
> > > Your perms are missing the "x" flag for the owner so no access is
> > > allowed. I recall a similar situation in another mailing list...
> > I don't want to *execute* the files, I want to *read* them.
>
> Don't you need exec perms for listing directories? ;-)
>
> ***
> sm01@stt008:~$ mkdir Desktop/test
>
> sm01@stt008:~$ ls -l Desktop | grep test
> drwxr-xr-x 2 sm01 sm01    48 may  1 21:14 test
>
> sm01@stt008:~$ ls -aFl Desktop/test
> total 1
> drwxr-xr-x  2 sm01 sm01  48 may  1 21:14 ./
> drwxr-xr-x 10 sm01 sm01 752 may  1 21:19 ../
>
> sm01@stt008:~$ chmod -x Desktop/test
>
> sm01@stt008:~$ ls -l Desktop | grep test
> drw-r--r-- 2 sm01 sm01    48 may  1 21:14 test
>
> sm01@stt008:~$ ls -aFl Desktop/test
> ls: no se puede acceder a Desktop/test/.: Permiso denegado
> ls: no se puede acceder a Desktop/test/..: Permiso denegado
> total 0
> ?????????? ? ? ? ?            ? .
> ?????????? ? ? ? ?            ? ..
> ***

Actually, the "x" permission on a directory means "search" (i.e. find  
a file in) the directory.  If you already know the name (or have  
guessed it) of a file in the directory and you have "--x" (no-read, no- 
write, yes-search) on the directory and 'r--' (read-only) on the file,  
you can read the file even though you can't read the directory.   
That's a feature, and it dates back to early days in UNIX.

What you are seeing is a corner case caused by that feature.  If you  
have "r--" on the directory you can read it, but you can't find any of  
the files whose names you can read.  So you can't get those files  
permission bits or mod-time's etc.  So "ls" fails in the bizarre way  
you are seeing.

So you can "read" the directory without the "x" bit, but it doesn't do  
you a fat load of good.

Enjoy!

Rick