Re: mkdir and ls display

[Pádraig Brady]

On 09/11/15 14:54, Ngô Huy wrote:
> Dear Padraig,
> 
> 2015-11-09 18:20 GMT+07:00 Pádraig Brady <address@hidden 
> <mailto:address@hidden>>:
> 
>     On 09/11/15 08:30, Ngô Huy wrote:
>     > Dear guys,
>     >
>     > I had problem with mkdir and ls when I used command:
>     >
>     > mkdir "* /" && mkdir "* /etc" && ls.
>     >
>     > It only displayed *.
> 
>     Note as yet unreleased version of ls will use shell quoting
>     to give a less ambiguous output:
> 
>     $ ls
>     '* '
> 
>     > But
>     >
>     > find . -type d -print
>     >
>     > display ./* /etc.
>     >
>     > If we have hidden directory and use xargs with find to execute some 
> command, it's security risk. Should we patch it's behavior ?
> 
>     I think you're worried about the '*' being expanded?
>     Or maybe the xargs splitting on the space.
>     In any case you can use `find ... -print0 | xargs -0`
>     to handle that.
> 
>     Not something that mkdir (coreutils) should be worried
>     about in any case.
> 
> I see this, but when use mkdir "* /" && mkdir "* /etc", it shouldn't be / in 
> file name, right ?

I don't see the issue here. mkdir is just passing down to the mkdir syscall
to create the "* /etc" dir, i.e. the 'etc' dir in the already created '* ' dir.

> We try to avoid incident problem, I think we should limit file name's 
> character.

That would have to be done at the kernel level.
There have been proposals with POSIX to use a restricted character set for file 
names.

thanks,
Pádraig.