[CentOS] mkdir this "." directory

[adrian kok]

Hi 

I have this . folder under tmp

1/ How they can make it this folder?

2/ How can I remove it?

Thank you

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Re: [CentOS] mkdir this "." directory

[Larry Brower]

adrian kok wrote:
Hi 


I have this . folder under tmp

1/ How they can make it this folder?



Please provide the output of ls -la /tmp

Are you referring to ./ or actually something like \\./ ?




2/ How can I remove it?



If it is really ./ then you dont as this is /tmp
If it is \\./ then rm -vr /tmp/\\.




Thank you

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Re: [CentOS] mkdir this "." directory

[Jason Pyeron]

> -Original Message-
> From: centos-boun...@centos.org 
> [mailto:centos-boun...@centos.org] On Behalf Of adrian kok
> Sent: Monday, December 28, 2009 18:50
> To: centos@centos.org
> Subject: [CentOS] mkdir this "." directory
> 
> Hi 
> 
> I have this . folder under tmp
> 
> 1/ How they can make it this folder?

cd .

> 
> 2/ How can I remove it?
>

cd ..

rmdir tmp
 
> Thank you
> 
> Send instant messages to your online friends 
> http://uk.messenger.yahoo.com 
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> 


I am not sure if this is a joke or not.

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Re: [CentOS] mkdir this "." directory

[Jason Pyeron]

 

> -Original Message-
> From: centos-boun...@centos.org 
> [mailto:centos-boun...@centos.org] On Behalf Of Larry Brower
> Sent: Monday, December 28, 2009 18:58
> To: CentOS mailing list
> Subject: Re: [CentOS] mkdir this "." directory
> 
> adrian kok wrote:
> > Hi
> > 
> > I have this . folder under tmp
> > 
> > 1/ How they can make it this folder?
> > 
> 
> Please provide the output of ls -la /tmp
> 
> Are you referring to ./ or actually something like \\./ ?

Either would not show up as a single .

> 
> 
> 
> > 2/ How can I remove it?
> > 
> 
> If it is really ./ then you dont as this is /tmp If it is 
> \\./ then rm -vr /tmp/\\.
> 
> 
> 
> > Thank you
> > 
> > Send instant messages to your online friends 
> > http://uk.messenger.yahoo.com 
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> > http://lists.centos.org/mailman/listinfo/centos
> 
> 



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Re: [CentOS] mkdir this "." directory

[John R Pierce]

adrian kok wrote:
> Hi 
>
> I have this . folder under tmp
>
> 1/ How they can make it this folder?
>
> 2/ How can I remove it?
>   

first you gotta figure out its -real- name.   most likely, its " ."  or 
". "   but the space could also be an unprintable character.


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Re: [CentOS] mkdir this "." directory

[Les Bell]

adrian kok  wrote:

>>
I have this . folder under tmp
<<

It's called a directory, not a "folder" and there's one in every directory.
It's a hard link to the current directory, just like ".." is a hard link to
the directory above.

>>
1/ How they can make it this folder?
<<

Create any directory, and it will appear, as I've explained.

>>
2/ How can I remove it?
<<

If you remove it, you'll be removing the /tmp directory itself, which is
not a bright idea. Imagine someone sitting on a branch, sawing away between
themselves and the trunk of the tree. . .

Best,

--- Les Bell
[http://www.lesbell.com.au]
Tel: +61 2 9451 1144


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Re: [CentOS] mkdir this "." directory

[Mike A. Harris]

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adrian kok wrote:
> Hi 
> 
> I have this . folder under tmp
> 
> 1/ How they can make it this folder?
> 
> 2/ How can I remove it?

Thanks, I just about spit my coffee out my nose when I read this, but it
made my day.  :)


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Re: [CentOS] mkdir this "." directory

[Eero Volotinen]

On 12/29/09 1:41 PM, Mike A. Harris wrote:
> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
>
> adrian kok wrote:
>> Hi
>>
>> I have this . folder under tmp
>>
>> 1/ How they can make it this folder?
>>
>> 2/ How can I remove it?
>
> Thanks, I just about spit my coffee out my nose when I read this, but it
> made my day.  :)

Last day of vacation :D . http://dban.sf.net is recommended for removing 
"." directories from harddisks..

--
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RHCE
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Re: [CentOS] mkdir this "." directory

[Ugo Bellavance]

On 2009-12-28 18:49, adrian kok wrote:
> Hi
>
> I have this . folder under tmp

It is a system-generated link to the current directory.  Don't touch that.

Ugo


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Re: [CentOS] mkdir this "." directory

[m . roth]

> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
>
> adrian kok wrote:
>> Hi
>>
>> I have this . folder under tmp
>>
>> 1/ How they can make it this folder?
>>
>> 2/ How can I remove it?
>
> Thanks, I just about spit my coffee out my nose when I read this, but it
> made my day.  :)
>
Don't do that - you'll wind up with too much blood in your caffeine
stream 

mark

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Re: [CentOS] mkdir this "." directory

[Anne Wilson]

On Tuesday 29 December 2009 13:59:43 Ugo Bellavance wrote:
> On 2009-12-28 18:49, adrian kok wrote:
> > Hi
> >
> > I have this . folder under tmp
> 
> It is a system-generated link to the current directory.  Don't touch that.
> 
Thank heavens there's one sane person reading today.  Obviously no-one else 
here was ever new to Linux. 

Anne
-- 
KDE Community Working Group
New to KDE Software? - get help from http://userbase.kde.org


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Re: [CentOS] mkdir this "." directory

[Marko Vojinovic]

On Tuesday 29 December 2009 14:46:23 Anne Wilson wrote:
> On Tuesday 29 December 2009 13:59:43 Ugo Bellavance wrote:
> > On 2009-12-28 18:49, adrian kok wrote:
> > > Hi
> > >
> > > I have this . folder under tmp
> >
> > It is a system-generated link to the current directory.  Don't touch
> > that.
> 
> Thank heavens there's one sane person reading today.  Obviously no-one else
> here was ever new to Linux.

You mean new to the concept of files and directories? This is not Linux-only. 
The . and .. existed even in MS-DOS back in the 80's. And they still exist, 
actually. The problem is that today people working under Windows [7|Vista|XP] 
never get to open a terminal anymore, and various GUI's play smart with them 
and don't show the links to current and parent directories.

Best, :-)
Marko

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Re: [CentOS] mkdir this "." directory

[Timo Schoeler]

Marko Vojinovic wrote:
> On Tuesday 29 December 2009 14:46:23 Anne Wilson wrote:
>> On Tuesday 29 December 2009 13:59:43 Ugo Bellavance wrote:
>>> On 2009-12-28 18:49, adrian kok wrote:
 Hi

 I have this . folder under tmp
>>> It is a system-generated link to the current directory.  Don't touch
>>> that.
>> Thank heavens there's one sane person reading today.  Obviously no-one else
>> here was ever new to Linux.
> 
> You mean new to the concept of files and directories? This is not Linux-only. 
> The . and .. existed even in MS-DOS back in the 80's. And they still exist, 
> actually. The problem is that today people working under Windows [7|Vista|XP] 
> never get to open a terminal anymore, and various GUI's play smart with them 
> and don't show the links to current and parent directories.

Sure, but: Nobody's guilty *not* to have seen this stuff in her/his
whole life just because she/he never looked at it. There may be multiple
reasons for that, one of them may be a simple 'I was born in 1996 and
never had the chance to work with CP/M'. ;)

> Best, :-)
> Marko

Regards,

Timo
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Re: [CentOS] mkdir this "." directory

[Bob McConnell]

Timo Schoeler wrote:
> Marko Vojinovic wrote:
>> On Tuesday 29 December 2009 14:46:23 Anne Wilson wrote:
>>> On Tuesday 29 December 2009 13:59:43 Ugo Bellavance wrote:
 On 2009-12-28 18:49, adrian kok wrote:
> Hi
>
> I have this . folder under tmp
 It is a system-generated link to the current directory.  Don't touch
 that.
>>> Thank heavens there's one sane person reading today.  Obviously no-one else
>>> here was ever new to Linux.
>> You mean new to the concept of files and directories? This is not 
>> Linux-only. 
>> The . and .. existed even in MS-DOS back in the 80's. And they still exist, 
>> actually. The problem is that today people working under Windows 
>> [7|Vista|XP] 
>> never get to open a terminal anymore, and various GUI's play smart with them 
>> and don't show the links to current and parent directories.
> 
> Sure, but: Nobody's guilty *not* to have seen this stuff in her/his
> whole life just because she/he never looked at it. There may be multiple
> reasons for that, one of them may be a simple 'I was born in 1996 and
> never had the chance to work with CP/M'. ;)

Never say "never". You still have the opportunity to work with CP/M, 
either with custom built hardware or any of a number of good simulators 
currently available on Source Forge. There is still an active Usenet 
newsgroup on the topic (comp.os.cpm), with hardware being designed and 
new kits being sold. Almost all of the source code is now available at 
.

Bob McConnell
N2SPP
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Re: [CentOS] mkdir this "." directory

[Timo Schoeler]

Bob McConnell wrote:
> Timo Schoeler wrote:
>> Marko Vojinovic wrote:
>>> On Tuesday 29 December 2009 14:46:23 Anne Wilson wrote:
 On Tuesday 29 December 2009 13:59:43 Ugo Bellavance wrote:
> On 2009-12-28 18:49, adrian kok wrote:
>> Hi
>>
>> I have this . folder under tmp
> It is a system-generated link to the current directory.  Don't touch
> that.
 Thank heavens there's one sane person reading today.  Obviously no-one else
 here was ever new to Linux.
>>> You mean new to the concept of files and directories? This is not 
>>> Linux-only. 
>>> The . and .. existed even in MS-DOS back in the 80's. And they still exist, 
>>> actually. The problem is that today people working under Windows 
>>> [7|Vista|XP] 
>>> never get to open a terminal anymore, and various GUI's play smart with 
>>> them 
>>> and don't show the links to current and parent directories.
>> Sure, but: Nobody's guilty *not* to have seen this stuff in her/his
>> whole life just because she/he never looked at it. There may be multiple
>> reasons for that, one of them may be a simple 'I was born in 1996 and
>> never had the chance to work with CP/M'. ;)
> 
> Never say "never". You still have the opportunity to work with CP/M, 
> either with custom built hardware or any of a number of good simulators 
> currently available on Source Forge. There is still an active Usenet 
> newsgroup on the topic (comp.os.cpm), with hardware being designed and 
> new kits being sold. Almost all of the source code is now available at 
> .

Sorry:

s/had the chance/was forced to/g

I still run IRIX, even NeXTSTEP -- just for fun; I run AIX on my
personal workstation. So, if there's anybody out there willing to have a
look at well designed/funny/whatever operating systems... ;)

> Bob McConnell
> N2SPP

Timo
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Re: [CentOS] mkdir this "." directory

[Jake Shipton]

On 28/12/09 23:49, adrian kok wrote:
> Hi 
> 
> I have this . folder under tmp
> 
> 1/ How they can make it this folder?
> 
> 2/ How can I remove it?
> 
> Thank you
> 
> Send instant messages to your online friends http://uk.messenger.yahoo.com 
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> 
> 
Your question may be amusing to some. Just take no notice of them :p

I'll give you a quick briefing though, you will find the "." in every
single directory, without it, you probably would be completely unable
to browse through directories at all.

The "." can be used as follows:

"cd ../" - This would step you to a lower directory. in other words you
would go from "/home/you/folder" to "/home/you"

This could also be used more for example to go from "/home/you/folder
/folder\ 2/" to simply the main "/" (This is the very top directory of
a drive) you could do:

"cd ../../../../" (or in this case you could cheat and just do "cd /",
but I'm just using this as an example ;-))

another use for the dots is like this:

"./configure" - Generally used when configuring make files, but this
tells the system to stay in directory in right now, and run that file.

Also could be used like this:

"sh ./shfile.sh" which pretty much does the same thing as above, only
this time your telling an application to run first, and then telling
the app to do above.

Oh and eh, do *not* delete those dots ;)

Also, you cannot create directory with just a dot. However, you could
make a directory starting with a dot.

For example ".folder" this will hide the directory from normal view
(However can still be seen given the right commands)

If you run with a gui, you'll probably have a few dotted folders in
your home dir. If so run "ls" and then "ls -a" and you'll see a few
folders magically appear. Bare in mind, if your out of ~ you will
need to pop back to it, to jump back to home dir just run "cd ~". :-)

Hope this helps :-)

-- 
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Re: [CentOS] mkdir this "." directory

[m . roth]

> Marko Vojinovic wrote:
>> On Tuesday 29 December 2009 14:46:23 Anne Wilson wrote:
>>> On Tuesday 29 December 2009 13:59:43 Ugo Bellavance wrote:
 On 2009-12-28 18:49, adrian kok wrote:
>
> I have this . folder under tmp
 It is a system-generated link to the current directory.  Don't touch
 that.
>>> Thank heavens there's one sane person reading today.  Obviously no-one
>>> else here was ever new to Linux.
>>
>> You mean new to the concept of files and directories? This is not
>> Linux-only.The . and .. existed even in MS-DOS back in the 80's. And
>> they still exist, actually. The problem is that today people working
>> under Windows [7|Vista|XP] never get to open a terminal anymore, and
>> various GUI's play smart with them
>> and don't show the links to current and parent directories.
>
> Sure, but: Nobody's guilty *not* to have seen this stuff in her/his
> whole life just because she/he never looked at it. There may be multiple
> reasons for that, one of them may be a simple 'I was born in 1996 and
> never had the chance to work with CP/M'. ;)

On the other hand, someone *is* guilty if they pick up something new, and
DON'T BOTHER TO RTFM, even cursorily.

mark

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Re: [CentOS] mkdir this "." directory

[John R Pierce]

Marko Vojinovic wrote:
> You mean new to the concept of files and directories? This is not Linux-only. 
> The . and .. existed even in MS-DOS back in the 80's. 

having an actual . and .. file in a directory is a distinctly Unix 
practice.   It leads to some funny behavior too, especially when 
combined with symlinks

for instance, say  /home/pierce is a symlink to /home2/pierce  and I'm 
in /home and go cd pierce, then go cd ..  in *some* unix systems, 
that cd .. takes me back to home, in others takes me to /home2





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Re: [CentOS] mkdir this "." directory

[Stephen Harris]

On Tue, Dec 29, 2009 at 10:21:01AM -0800, John R Pierce wrote:

> for instance, say  /home/pierce is a symlink to /home2/pierce  and I'm 
> in /home and go cd pierce, then go cd ..  in *some* unix systems, 
> that cd .. takes me back to home, in others takes me to /home2

It's actually shell dependent, not Unix platform dependent.  Some shells
(eg bash, ksh) perform parsing of the "cd" parameter and so will appear
to back-out of symlinks.  Other (typically older) shells just naively
do a chdir("..") call, which will take you to the real parent directory.

Sometimes both behaviours are useful, so I've created a function "up"

  up()
  {
cd "`/bin/pwd`/.."
  }

So...

  /home/sweh$ cd public_html
  /home/sweh/public_html$ cd ..
  /home/sweh$ cd public_html
  /home/sweh/public_html$ up
  /autofs/publish$ ls -l /home/sweh/public_html
  lrwxrwxrwx 1 sweh sweh 20 Jun  8  2008 /home/sweh/public_html -> 
/autofs/publish/public_html/

Symlinks combined with automounters... fun :-)

-- 

rgds
Stephen
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Re: [CentOS] mkdir this "." directory

[Benjamin Franz]

John R Pierce wrote:
> Marko Vojinovic wrote:
>   
>> You mean new to the concept of files and directories? This is not 
>> Linux-only. 
>> The . and .. existed even in MS-DOS back in the 80's. 
>> 
>
> having an actual . and .. file in a directory is a distinctly Unix 
> practice.   It leads to some funny behavior too, especially when 
> combined with symlinks

Umm. No. Try launching a 'cmd' shell under Windows (whatever version) 
and doing a 'dir' anywhere except the root directory and you will see 
'.' and '..' entries.

-- 

Benjamin Franz

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Re: [CentOS] mkdir this "." directory

[Marko Vojinovic]

On Tuesday 29 December 2009 18:21:01 John R Pierce wrote:
> Marko Vojinovic wrote:
> > You mean new to the concept of files and directories? This is not
> > Linux-only. The . and .. existed even in MS-DOS back in the 80's.
> 
> having an actual . and .. file in a directory is a distinctly Unix
> practice.

I was not trying to say that . and .. were *invented* in MS-DOS. I was just 
commenting that it is not Linux-specific (or Unix-specific). The point was that 
a newbie would encounter . and .. equally well on both Linux and Windows 
systems. The only difference is that Windows does not encourage the use of a 
terminal, unlike Linux. Therefore, the fact that someone is confused by the 
existence of . in some directory is mainly the fault of GUI-for-everything 
philosophy of Windows.

Best, :-)
Marko

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Re: [CentOS] mkdir this "." directory

[Bob McConnell]

Marko Vojinovic wrote:
> On Tuesday 29 December 2009 18:21:01 John R Pierce wrote:
>> Marko Vojinovic wrote:
>>> You mean new to the concept of files and directories? This is not
>>> Linux-only. The . and .. existed even in MS-DOS back in the 80's.
>> having an actual . and .. file in a directory is a distinctly Unix
>> practice.
> 
> I was not trying to say that . and .. were *invented* in MS-DOS. I was just 
> commenting that it is not Linux-specific (or Unix-specific). The point was 
> that 
> a newbie would encounter . and .. equally well on both Linux and Windows 
> systems. The only difference is that Windows does not encourage the use of a 
> terminal, unlike Linux. Therefore, the fact that someone is confused by the 
> existence of . in some directory is mainly the fault of GUI-for-everything 
> philosophy of Windows.

MS-DOS 2.0 added subdirectories, I/O redirection, pipes, filters and a 
few other features copied from Unix. Of course they were mere shadows of 
the actual Unix features and lacked most of the standard capabilities, 
but it was a step in the right direction. It is one of the few steps in 
that direction Microsoft ever took.

Bob McConnell
N2SPP
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Re: [CentOS] mkdir this "." directory

[Stephen Harris]

On Tue, Dec 29, 2009 at 04:06:09PM -0500, Bob McConnell wrote:
> MS-DOS 2.0 added subdirectories, I/O redirection, pipes, filters and a 

Ah, pipes... yeah, that was a fun implementation.  Because DOS was single
tasking the pipe actually wrote the data out to a temporary file, then
when the generating program finished the consumer program would be started
up to read from the temporary file.

Slow as hell on floppies!  And you'd better hope you had enough free space
on the disk :-)

-- 

rgds
Stephen
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Re: [CentOS] mkdir this "." directory

[Warren Young]

On 12/29/2009 11:49 AM, Benjamin Franz wrote:
> John R Pierce wrote:
>> Marko Vojinovic wrote:
>>
>>> You mean new to the concept of files and directories? This is not 
>>> Linux-only.
>>> The . and .. existed even in MS-DOS back in the 80's.
>>
>> having an actual . and .. file in a directory is a distinctly Unix
>> practice.   It leads to some funny behavior too, especially when
>> combined with symlinks
>
> Umm. No. Try launching a 'cmd' shell under Windows (whatever version)
> and doing a 'dir' anywhere except the root directory and you will see
> '.' and '..' entries.

The difference is that on Windows, there aren't really directory entries 
in the filesystem called "." and "..".  The Windows kernel has special 
knowledge that "." means "current directory" and ".." means "previous 
directory".  The Windows OS kernel is superficially mimicking Unix here, 
whereas Linux, like the solid Unix clone that it is, is actually 
exposing a literal truth about the underlying filesystem.

On any filesystem designed in the Unix Way, . and .. are actual 
directory entries, clear down to the lowest level of the filesystem. 
They are special in only two ways.  First, they're automatically created 
and destroyed as needed by the filesystem driver code to maintain a sane 
directory structure.  Second, they're hard links, something most Unixy 
filesystems don't normally allow with directories due to the potential 
for havoc.  These are the *only* distinctions these directory entries hold!

Let's do a little playing around to explore this:

$ mkdir foo
$ cd foo
$ ls -ld . | cut -f2 -d' '

If you do this on a Unixy filesystem, you will get '2', meaning that 
there are two references to this "foo" directory entry in the 
filesystem: one the actual directory entry named "foo" and the other the 
"." hard link within that directory which refers to the same directory 
entry in the filesystem.  Yes, there literally is a "." entry inside the 
"foo" directory, referring back to "foo", thus making the reference 
count 2, not 1 as you might naively expect.  A directory entry with a 
reference count of 0 or 1 would mean the filesystem is corrupted, and is 
one of the things fsck tries to detect and fix.

If you have a Windows box with Cygwin on it and try the above commands 
there, you get '1' instead.  Why?  Because '.' isn't actually a 
directory entry in the NTFS scheme.  It's fakery implemented under the 
hood to mimic the Unix way of referring to the current directory, not a 
real object as on a Unix system.

Still thinking this is just a distinction without a difference?  Okay, 
try this:

$ cd /
 $ ld -ld . | cut -f2 -d' '

I get 28 on one Linux box here.  Why 28?  Because there happen to be 25 
subdirectories off the top-level root on this system, each of which 
contain a ".." hard link back to the root, plus one each for "." and 
".." in the root directory, and one final one for the actual root 
directory entry.  28.  Notice how all of the ".."s are real hard links, 
each of which increases the reference count of the directory entry it 
refers to.  It also points out something else that goes back to the tail 
end of the text I quoted above, which is that there is a ".." in the 
root directory of a Unix file system.  It is special only in that it's a 
kind of loop-back, pointing to the same directory entry as the "." entry.

Try the above commands on Cygwin and you'll get 1 again, proving that . 
and .. are not actual parts of your Windows box's filesystem.  They're 
superficialities, papering over a great deal of complexity down at the 
NTFS implementation level.

This is just one of the many ways Unixy systems are actually simpler, 
more transparent, and easier to understand than Windows systems.  Both 
systems achieve the same end, but Unix does it in a more coherent way, 
with fewer concepts and special cases.
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Re: [CentOS] mkdir this "." directory

[m . roth]

> Marko Vojinovic wrote:
>> On Tuesday 29 December 2009 18:21:01 John R Pierce wrote:
>>> Marko Vojinovic wrote:
 You mean new to the concept of files and directories? This is not
 Linux-only. The . and .. existed even in MS-DOS back in the 80's.
>>> having an actual . and .. file in a directory is a distinctly Unix
>>> practice.
>>
>> I was not trying to say that . and .. were *invented* in MS-DOS. I was
>> just commenting that it is not Linux-specific (or Unix-specific).

>> terminal, unlike Linux. Therefore, the fact that someone is confused by
>> the existence of . in some directory is mainly the fault of
>> GUI-for-everything philosophy of Windows.

And Macs. I agree. To quote a friend, "your momma dresses you funny, and
you need a mouse to delete files!"
>
> MS-DOS 2.0 added subdirectories, I/O redirection, pipes, filters and a
> few other features copied from Unix. Of course they were mere shadows of
> the actual Unix features and lacked most of the standard capabilities,
> but it was a step in the right direction. It is one of the few steps in
> that direction Microsoft ever took.

Yeah, and 3.0 broke a number of things that were in 1.0 and 2.0; one of
the biggest mistakes M$ ever made was not introducing in 3.0 at least
foreground/background multitasking (you couldn't print and do anything
else!) and virtual memory. If they'd done that then, WinDoze wouldn't have
been the disaster it became with the 95 line.

  mark "the other, of course was putting the GUI in ring 0"

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