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os.stat() distorts filenames that end with period (nt.stat())

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  os.stat() distorts filenames that end with period (nt.stat()) ruck <john.ruckstuhl@gmail.com> - 2012-09-06 17:55 -0700
    Re: os.stat() distorts filenames that end with period (nt.stat()) Dave Angel <d@davea.name> - 2012-09-06 21:18 -0400
      Re: os.stat() distorts filenames that end with period (nt.stat()) ruck <john.ruckstuhl@gmail.com> - 2012-09-06 18:54 -0700
      Re: os.stat() distorts filenames that end with period (nt.stat()) ruck <john.ruckstuhl@gmail.com> - 2012-09-06 18:54 -0700
    Re: os.stat() distorts filenames that end with period (nt.stat()) alex23 <wuwei23@gmail.com> - 2012-09-06 18:49 -0700
      Re: os.stat() distorts filenames that end with period (nt.stat()) ruck <john.ruckstuhl@gmail.com> - 2012-09-06 19:46 -0700
    Re: os.stat() distorts filenames that end with period (nt.stat()) Terry Reedy <tjreedy@udel.edu> - 2012-09-06 22:05 -0400
      Re: os.stat() distorts filenames that end with period (nt.stat()) ruck <john.ruckstuhl@gmail.com> - 2012-09-06 22:54 -0700
      Re: os.stat() distorts filenames that end with period (nt.stat()) ruck <john.ruckstuhl@gmail.com> - 2012-09-06 22:54 -0700
    Re: os.stat() distorts filenames that end with period (nt.stat()) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-09-07 02:32 +0000
    Re: os.stat() distorts filenames that end with period (nt.stat()) Ian Kelly <ian.g.kelly@gmail.com> - 2012-09-06 21:12 -0600

#28653 — os.stat() distorts filenames that end with period (nt.stat())

(This with Python 2.7.2 on Windows 7)

os.stat() won't recognize a filename ending in period.
It will ignore trailing periods.  
If you ask it about file 'goo...' it will report on file 'goo'
And if 'goo' doesn't exist, os.stat will complain.

create file goo, then

    >>> os.stat('goo')
    nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
    >>> os.stat('goo...')
    nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)

rename goo to "goo...", then,

    >>> os.stat('goo...')

    Traceback (most recent call last):
      File "<pyshell#16>", line 1, in <module>
        os.stat('goo...')
    WindowsError: [Error 2] The system cannot find the file specified: 'goo...'

Puzzling, to me at least.
Any comments?
This with Python 2.7.2 on Windows 7.
Is there a workaround?
Thanks,
John

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#28659

On 09/06/2012 08:55 PM, ruck wrote:
> (This with Python 2.7.2 on Windows 7)
>
> os.stat() won't recognize a filename ending in period.
> It will ignore trailing periods.  
> If you ask it about file 'goo...' it will report on file 'goo'
> And if 'goo' doesn't exist, os.stat will complain.
>
> create file goo, then
>
>     >>> os.stat('goo')
>     nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
>     >>> os.stat('goo...')
>     nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
>
> rename goo to "goo...", then,
>
>     >>> os.stat('goo...')
>
>     Traceback (most recent call last):
>       File "<pyshell#16>", line 1, in <module>
>         os.stat('goo...')
>     WindowsError: [Error 2] The system cannot find the file specified: 'goo...'
>
> Puzzling, to me at least.
> Any comments?
> This with Python 2.7.2 on Windows 7.
> Is there a workaround?
> Thanks,
> John

FWIW, it seems to work okay here in Linux 11.04, both Python 2.7 and 3.2


-- 

DaveA

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#28665

On Thursday, September 6, 2012 6:19:11 PM UTC-7, Dave Angel wrote:
> On 09/06/2012 08:55 PM, ruck wrote:
> 
> > (This with Python 2.7.2 on Windows 7)
> 
> >
> 
> > os.stat() won't recognize a filename ending in period.
> 
> > It will ignore trailing periods.  
> 
> > If you ask it about file 'goo...' it will report on file 'goo'
> 
> > And if 'goo' doesn't exist, os.stat will complain.
> 
> >
> 
> > create file goo, then
> 
> >
> 
> >     >>> os.stat('goo')
> 
> >     nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >     >>> os.stat('goo...')
> 
> >     nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >
> 
> > rename goo to "goo...", then,
> 
> >
> 
> >     >>> os.stat('goo...')
> 
> >
> 
> >     Traceback (most recent call last):
> 
> >       File "<pyshell#16>", line 1, in <module>
> 
> >         os.stat('goo...')
> 
> >     WindowsError: [Error 2] The system cannot find the file specified: 'goo...'
> 
> >
> 
> > Puzzling, to me at least.
> 
> > Any comments?
> 
> > This with Python 2.7.2 on Windows 7.
> 
> > Is there a workaround?
> 
> > Thanks,
> 
> > John
> 
> 
> 
> FWIW, it seems to work okay here in Linux 11.04, both Python 2.7 and 3.2
> 
> 
> 
> 
> 
> -- 
> 
> 
> 
> DaveA

Thanks, I agree, I expect this is Windows 7 or win32 specific.

Also, in creating a test case to demonstrate, I may have clouded my intent.
I want to walk() a dir, 
reporting the output of os.stat() for files below the dir.
One of the existing files happens to be named like "goo..."
And os.stat('goo...') fails to see the file.
I am not trying to rename the file, just hoping to stat an existing file.
John

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#28666

On Thursday, September 6, 2012 6:19:11 PM UTC-7, Dave Angel wrote:
> On 09/06/2012 08:55 PM, ruck wrote:
> 
> > (This with Python 2.7.2 on Windows 7)
> 
> >
> 
> > os.stat() won't recognize a filename ending in period.
> 
> > It will ignore trailing periods.  
> 
> > If you ask it about file 'goo...' it will report on file 'goo'
> 
> > And if 'goo' doesn't exist, os.stat will complain.
> 
> >
> 
> > create file goo, then
> 
> >
> 
> >     >>> os.stat('goo')
> 
> >     nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >     >>> os.stat('goo...')
> 
> >     nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >
> 
> > rename goo to "goo...", then,
> 
> >
> 
> >     >>> os.stat('goo...')
> 
> >
> 
> >     Traceback (most recent call last):
> 
> >       File "<pyshell#16>", line 1, in <module>
> 
> >         os.stat('goo...')
> 
> >     WindowsError: [Error 2] The system cannot find the file specified: 'goo...'
> 
> >
> 
> > Puzzling, to me at least.
> 
> > Any comments?
> 
> > This with Python 2.7.2 on Windows 7.
> 
> > Is there a workaround?
> 
> > Thanks,
> 
> > John
> 
> 
> 
> FWIW, it seems to work okay here in Linux 11.04, both Python 2.7 and 3.2
> 
> 
> 
> 
> 
> -- 
> 
> 
> 
> DaveA

Thanks, I agree, I expect this is Windows 7 or win32 specific.

Also, in creating a test case to demonstrate, I may have clouded my intent.
I want to walk() a dir, 
reporting the output of os.stat() for files below the dir.
One of the existing files happens to be named like "goo..."
And os.stat('goo...') fails to see the file.
I am not trying to rename the file, just hoping to stat an existing file.
John

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#28664

On Sep 7, 10:55 am, ruck <john.ruckst...@gmail.com> wrote:
> (This with Python 2.7.2 on Windows 7)
> rename goo to "goo...", then,

I'm unable to rename any file to have a '...' suffix, are you certain
the file exists in the form you think after the rename?

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#28673

On Thursday, September 6, 2012 6:49:43 PM UTC-7, alex23 wrote:
> On Sep 7, 10:55 am, ruck <john.ruckst...@gmail.com> wrote:
> 
> > (This with Python 2.7.2 on Windows 7)
> 
> > rename goo to "goo...", then,
> 
> 
> 
> I'm unable to rename any file to have a '...' suffix, are you certain
> 
> the file exists in the form you think after the rename?

I see your point.  Using cygwin bash, I have no problem naming files with '...' suffix.  But I see you're right, it seems I cannot do so from Windows Explorer or from cmd shell.
FWIW, Windows Explorer displays to me that the file is named with '...' suffix.
John

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#28669

On 9/6/2012 8:55 PM, ruck wrote:
> (This with Python 2.7.2 on Windows 7)
>
> os.stat() won't recognize a filename ending in period.
> It will ignore trailing periods.
> If you ask it about file 'goo...' it will report on file 'goo'
> And if 'goo' doesn't exist, os.stat will complain.
>
> create file goo, then
>
>      >>> os.stat('goo')
>      nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
>      >>> os.stat('goo...')
>      nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
>
> rename goo to "goo...", then,
>
>      >>> os.stat('goo...')
>
>      Traceback (most recent call last):
>        File "<pyshell#16>", line 1, in <module>
>          os.stat('goo...')
>      WindowsError: [Error 2] The system cannot find the file specified: 'goo...'
>
> Puzzling, to me at least.
> Any comments?

Windows have restrictions on filenames. The restrictions are not 
consistent in that some parts of Windows will let you make names that 
other parts do not recognize or regard as illegal. I ran into this some 
years ago and there may be a discussion on the tracker, but I have 
forgetten the details except that one of the 'parts' was Windows 
Explorer. This *might* be what you are running into.

-- 
Terry Jan Reedy

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#28679

On Thursday, September 6, 2012 7:05:39 PM UTC-7, Terry Reedy wrote:
> On 9/6/2012 8:55 PM, ruck wrote:
> 
> > (This with Python 2.7.2 on Windows 7)
> 
> >
> 
> > os.stat() won't recognize a filename ending in period.
> 
> > It will ignore trailing periods.
> 
> > If you ask it about file 'goo...' it will report on file 'goo'
> 
> > And if 'goo' doesn't exist, os.stat will complain.
> 
> >
> 
> > create file goo, then
> 
> >
> 
> >      >>> os.stat('goo')
> 
> >      nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >      >>> os.stat('goo...')
> 
> >      nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >
> 
> > rename goo to "goo...", then,
> 
> >
> 
> >      >>> os.stat('goo...')
> 
> >
> 
> >      Traceback (most recent call last):
> 
> >        File "<pyshell#16>", line 1, in <module>
> 
> >          os.stat('goo...')
> 
> >      WindowsError: [Error 2] The system cannot find the file specified: 'goo...'
> 
> >
> 
> > Puzzling, to me at least.
> 
> > Any comments?
> 
> 
> 
> Windows have restrictions on filenames. The restrictions are not 
> 
> consistent in that some parts of Windows will let you make names that 
> 
> other parts do not recognize or regard as illegal. I ran into this some 
> 
> years ago and there may be a discussion on the tracker, but I have 
> 
> forgetten the details except that one of the 'parts' was Windows 
> 
> Explorer. This *might* be what you are running into.
> 
> 
> 
> -- 
> 
> Terry Jan Reedy

Summary:
I was complaining that
    >>> os.stat('goo...')

    Traceback (most recent call last):
      File "<pyshell#35>", line 1, in <module>
        os.stat('goo...')
    WindowsError: [Error 2] The system cannot find the file specified: 'goo...'

is actually looking for file 'goo' instead of the existing file 'goo...' -- that's why it errors.  
(Python 2.7.2, Windows 7)

Here's a workaround.
    >>> os.stat('\\\\?\\' + os.getcwd() + '\\' + 'goo...')
    nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0,
    st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, 
    st_ctime=1346978160L)

In other words, prefix the path (full path?) with \\?\ to disable the Windows API filename  interceptions.

Detail:
    "Naming Files, Paths, and Namespaces" ( http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx )
says

  Naming Conventions
  The following fundamental rules enable applications to 
  create and process valid names for files and directories, 
  regardless of the file system:
  
  * Do not end a file or directory name with a space or a 
  period. Although the underlying file system may support 
  such names, the Windows shell and user interface does not. 

In my case, the filesystem is NTFS and it does support filenames like 'goo...', and I'm not trying to use Windows shell or UI.  So how do I get to the underlying filesystem without interference?  Here (from the same reference)

  Namespaces
  There are two main categories of namespace conventions 
  used in the Windows APIs, commonly referred to as NT 
  namespaces and the Win32 namespaces.  ...

  Win32 File Namespaces
  The Win32 namespace prefixing and conventions are 
  summarized in this section and the following section, 
  with descriptions of how they are used. Note that these 
  examples are intended for use with the Windows API 
  functions and do not all necessarily work with Windows 
  shell applications such as Windows Explorer. For this 
  reason there is a wider range of possible paths than is 
  usually available from Windows shell applications, and 
  Windows applications that take advantage of this can be 
  developed using these namespace conventions.

  For file I/O, the "\\?\" prefix to a path string tells 
  the Windows APIs to disable all string parsing and to 
  send the string that follows it straight to the file 
  system. For example, if the file system supports large 
  paths and file names, you can exceed the MAX_PATH limits 
  that are otherwise enforced by the Windows APIs.

Thanks all for your comments and pointers.
John

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#28680

On Thursday, September 6, 2012 7:05:39 PM UTC-7, Terry Reedy wrote:
> On 9/6/2012 8:55 PM, ruck wrote:
> 
> > (This with Python 2.7.2 on Windows 7)
> 
> >
> 
> > os.stat() won't recognize a filename ending in period.
> 
> > It will ignore trailing periods.
> 
> > If you ask it about file 'goo...' it will report on file 'goo'
> 
> > And if 'goo' doesn't exist, os.stat will complain.
> 
> >
> 
> > create file goo, then
> 
> >
> 
> >      >>> os.stat('goo')
> 
> >      nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >      >>> os.stat('goo...')
> 
> >      nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0, st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, st_ctime=1346978160L)
> 
> >
> 
> > rename goo to "goo...", then,
> 
> >
> 
> >      >>> os.stat('goo...')
> 
> >
> 
> >      Traceback (most recent call last):
> 
> >        File "<pyshell#16>", line 1, in <module>
> 
> >          os.stat('goo...')
> 
> >      WindowsError: [Error 2] The system cannot find the file specified: 'goo...'
> 
> >
> 
> > Puzzling, to me at least.
> 
> > Any comments?
> 
> 
> 
> Windows have restrictions on filenames. The restrictions are not 
> 
> consistent in that some parts of Windows will let you make names that 
> 
> other parts do not recognize or regard as illegal. I ran into this some 
> 
> years ago and there may be a discussion on the tracker, but I have 
> 
> forgetten the details except that one of the 'parts' was Windows 
> 
> Explorer. This *might* be what you are running into.
> 
> 
> 
> -- 
> 
> Terry Jan Reedy

Summary:
I was complaining that
    >>> os.stat('goo...')

    Traceback (most recent call last):
      File "<pyshell#35>", line 1, in <module>
        os.stat('goo...')
    WindowsError: [Error 2] The system cannot find the file specified: 'goo...'

is actually looking for file 'goo' instead of the existing file 'goo...' -- that's why it errors.  
(Python 2.7.2, Windows 7)

Here's a workaround.
    >>> os.stat('\\\\?\\' + os.getcwd() + '\\' + 'goo...')
    nt.stat_result(st_mode=33206, st_ino=0L, st_dev=0, st_nlink=0, st_uid=0,
    st_gid=0, st_size=0L, st_atime=1346978160L, st_mtime=1346978160L, 
    st_ctime=1346978160L)

In other words, prefix the path (full path?) with \\?\ to disable the Windows API filename  interceptions.

Detail:
    "Naming Files, Paths, and Namespaces" ( http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx )
says

  Naming Conventions
  The following fundamental rules enable applications to 
  create and process valid names for files and directories, 
  regardless of the file system:
  
  * Do not end a file or directory name with a space or a 
  period. Although the underlying file system may support 
  such names, the Windows shell and user interface does not. 

In my case, the filesystem is NTFS and it does support filenames like 'goo...', and I'm not trying to use Windows shell or UI.  So how do I get to the underlying filesystem without interference?  Here (from the same reference)

  Namespaces
  There are two main categories of namespace conventions 
  used in the Windows APIs, commonly referred to as NT 
  namespaces and the Win32 namespaces.  ...

  Win32 File Namespaces
  The Win32 namespace prefixing and conventions are 
  summarized in this section and the following section, 
  with descriptions of how they are used. Note that these 
  examples are intended for use with the Windows API 
  functions and do not all necessarily work with Windows 
  shell applications such as Windows Explorer. For this 
  reason there is a wider range of possible paths than is 
  usually available from Windows shell applications, and 
  Windows applications that take advantage of this can be 
  developed using these namespace conventions.

  For file I/O, the "\\?\" prefix to a path string tells 
  the Windows APIs to disable all string parsing and to 
  send the string that follows it straight to the file 
  system. For example, if the file system supports large 
  paths and file names, you can exceed the MAX_PATH limits 
  that are otherwise enforced by the Windows APIs.

Thanks all for your comments and pointers.
John

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#28672

On Thu, 06 Sep 2012 17:55:02 -0700, ruck wrote:

> (This with Python 2.7.2 on Windows 7)
> 
> os.stat() won't recognize a filename ending in period. It will ignore
> trailing periods.
> If you ask it about file 'goo...' it will report on file 'goo' And if
> 'goo' doesn't exist, os.stat will complain.


I don't have access to a Windows machine to test this, but I suspect that 
you have found a side-effect of a Windows bug.

http://answers.microsoft.com/en-us/windows/forum/windows_7-files/files-disappear-when-you-append-a-period-to-a/4329b1f1-746e-4c45-9c32-75622b6ab526

http://support.microsoft.com/kb/115827



-- 
Steven

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#28674

On Thu, Sep 6, 2012 at 6:55 PM, ruck <john.ruckstuhl@gmail.com> wrote:
> (This with Python 2.7.2 on Windows 7)
>
> os.stat() won't recognize a filename ending in period.
> It will ignore trailing periods.
> If you ask it about file 'goo...' it will report on file 'goo'
> And if 'goo' doesn't exist, os.stat will complain.

Due to the weirdness of Windows filename extensions, these names refer
to the same file.

C:\Users\Ian>echo hello > goo

C:\Users\Ian>type goo
hello

C:\Users\Ian>type goo.
hello

C:\Users\Ian>type goo..
hello

C:\Users\Ian>type goo...
hello

C:\Users\Ian>echo world > goo...

C:\Users\Ian>dir goo*
 Volume in drive C is OS
 Volume Serial Number is 9881-66F0

 Directory of C:\Users\Ian

09/06/2012  09:10 PM                 8 goo
               1 File(s)              8 bytes
               0 Dir(s)   8,884,142,080 bytes free

C:\Users\Ian>type goo
world

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