Actually, in this case, I think it's the .NET MAX_PATH (260). .NET itself, in its PathHelper class, doesn't accept the '\\?\' syntax and explicitly throws an exception if the path exceeds 259 (ANSI) or 129 (Unicode). This class is used all over .NET.
Now, .NET CORE has been enhanced to support long paths. But that isn't today... for most people. There are a few libraries (third party) you can use to add this support to PowerShell. They basically wrap the low-level APIs using P/Invoke (which you can do yourself, with Add-Type). They are much lower impact than installing Cygwin, but still... I guess my question is this: what are you really trying to do? Cmd.exe and the subst command are still my "go to solution" for long paths. You can also fake this in PowerShell with New-PsDrive (or "net share...") if you absolutely must stay in PowerShell, but it gets a little nasty if you need to worry about junctions. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Kurt Buff Sent: Wednesday, December 30, 2015 4:13 PM To: [email protected] Subject: [powershell] Long file names - again... All, If anyone can help, I'd much appreciate it. I'm picking up where I left off some time ago in auditing our file server. I used robocopy to generate a list of files for each drive on our file server - all told over 10.3m lines, massaged the output (with findstr) to break it up by drive letter and to remove directories and things like $recycle.bin and 'system volume', then further massaged the output to remove the extraneous robocopy markings. I had to break it into smaller files by partition because processing the file in powershell overran RAM on a 16g machine. I then took each line (which looked like, e.g. i:\somedirectory\otherdirectory\file), then prepended '\\?\' to each line), because some number of the files have path lengths greater than 260 characters, and I'm hoping that using this specification will allow access to those files without adding funky 3rd party tools. So, I've ended up with a set of text files that have many lines that look like this: \\?\i:\somedirectory\otherdirectory\file What I'm trying to do is illustrated by the following, but I'm getting no output from it - it just returns without any output after a few moments. $files = get-content c:\batchfiles\file-i.txt foreach ( $file in $files ) { get-childitem $file | select length, fullname } However, if I strip the '\\?\' from each line, it does what I want - but of course the script fails as soon as it encounters a file that has a name/directory specification that exceeds the Win32 API limit. I've tried surrounding the string with both double and single quotes, and still no joy. A simpler example tells the tale: This works, except for long file names: gci i:\somedirectory\otherdirectory\file These fail silently: gci \\?\i:\somedirectory\otherdirectory\file gci "\\?\i:\somedirectory\otherdirectory\file" gci '\\?\i:\somedirectory\otherdirectory\file' These fail with an error: gci "\\\\?\\i:\somedirectory\otherdirectory\file" gci '\\\\?\\i:\somedirectory\otherdirectory\file' The error is: Get-ChildItem : Cannot retrieve the dynamic parameters for the cmdlet. Cannot process argument because the value of argument "path" is not valid. Change the value of the "path" argument and run the operation again. At line:1 char:1 + gci "\\\\?\\i:\CFRemoteImages\Air Canada Montreal STOC.vhd" | select length, ful ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidArgument: (:) [Get-ChildItem], ParameterBindingException + FullyQualifiedErrorId : GetDynamicParametersException,Microsoft.PowerShell.Commands.GetChildItemCommand ================================================ Did you know you can also post and find answers on PowerShell in the forums? http://www.myitforum.com/forums/default.asp?catApp=1 ================================================ Did you know you can also post and find answers on PowerShell in the forums? http://www.myitforum.com/forums/default.asp?catApp=1
