[p4] Windows file name length issues

David Weintraub qazwart at gmail.com
Sat Aug 18 19:38:49 PDT 2007


Yes, the MAX_PATH is set to only 255. I knew that the Win32 API is
suppose to support names as long as 32K, and I knew that NTFS supports
that. It's one of the things MS people keep bringing up to me. And,
all are shocked when I show them that I cannot create a file longer
than 255 characters in Windows Explorer.

I heard there was a workaround, but I know few programs that actually
support it.

Does Vista have the same MAX_PATH limitation?

On 8/17/07, Patrick Bennett <patrick.bennett at inin.com> wrote:
> No, the Win32 APIs supports very long filenames (up to 32k), it's just
> that it requires some programmatic contortions that very few programs
> make, so the default 255 limit is still very commonly run into.
> To use long filenames, programs have to call the Unicode versions (the
> 'W' versions - ie CreateFileW) with \\?\ prepended to the path.
> These longer paths have been supported since, I believe, the first
> Windows NT version (3.5 as I vaguelly recall - it was a long time ago).
> Windows 95/98/ME are limited to 255.
>
> Patrick Bennett
>
> David Weintraub wrote:
> > On 8/17/07, Robert Cowham <robert at vaccaperna.co.uk> wrote:
> >
> >> I don't think it is a Windows OS limitation, but instead an Office
> >> limitation - i.e. versions of Word/Excel can't cope.
> >>
> >
> > I've even argued with Microsoft people on this point. NTFS can handle
> > file names of upto 32K long with each component of the path having up
> > to 255 characters in length. And, Windows *ALMOST* supports this.
> >
> > The problem is that the Windows routine that actually fetches the file
> > from the computer is limited to 255 characters (253 if you include the
> > directory specifier). This was true up to Windows XP. I don't know if
> > the problem exists in Windows Vista or not (and because of the
> > limitation in earlier versions of Windows, that might be why MS Office
> > is also limited).
> >
> > The only way around this is to shorten the path you use. Put your
> > Perforce clients directly on the root of the drive, and not in your My
> > Documents folder or your desktop. These actually sit pretty deeply in
> > the drive under "C:\Documents and Settings\<UserName>". This alone
> > will save you somewhere between 30 to 40 characters in the file path.
> >
> > The other way is shortening your path in the client. Most Windows
> > users map the Depot root to the root of their client, but this eats up
> > a lot of file name length. By simply mapping only the part you need on
> > your disk can save another 20 to 30 characters. You can also shorten
> > long directory names in your depot when you map them to your client.
> >
> > Otherwise, this is really a limit with the OS, and there is no easy
> > way around it.
> >
> > On 8/17/07, Robert Cowham <robert at vaccaperna.co.uk> wrote:
> >
> >> I don't think it is a Windows OS limitation, but instead an Office
> >> limitation - i.e. versions of Word/Excel can't cope.
> >>
> >> http://support.microsoft.com/kb/326039
> >>
> >> Thus no Vista solution!!
> >>
> >> Shortening Client root/mapping can help...
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: perforce-user-bounces at perforce.com
> >>> [mailto:perforce-user-bounces at perforce.com] On Behalf Of
> >>> Albrecht, Matt
> >>>
> >>> Sent: 17 August 2007 16:26
> >>> To: perforce-user at perforce.com
> >>> Subject: [p4] Windows file name length issues
> >>>
> >>> Recently, the Windows users at my office have started
> >>> experiencing the Windows file name length limit, where, due
> >>> to the length of their client root directory, the Perforce
> >>> client cannot sync the file to the local client due to the
> >>> total local file name length being more than 255 characters
> >>> (or right around there). They are all running on Windows XP.
> >>>
> >>> The current answer I have is to either change the file names
> >>> so that they're more compatible with everyone's system (not a
> >>> good answer), or to shorten the client root (seems like a
> >>> short term fix).
> >>>
> >>> Does anyone know of a better, long term solution, or if
> >>> Perforce on Vista has the same problem?  Thanks.
> >>>
> >> _______________________________________________
> >> perforce-user mailing list  -  perforce-user at perforce.com
> >> http://maillist.perforce.com/mailman/listinfo/perforce-user
> >>
> >>
> >
> >
> >
>
>
> --
>
> *Patrick Bennett* | Software Engineer
> phone & fax +1.317.715.8302 | patrick.bennett at inin.com
>
> *Interactive Intelligence Inc.*
> Deliberately Innovative
> www.inin.com <http://www.inin.com/>
>
>
>


-- 
--
David Weintraub
qazwart at gmail.com



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