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Best way to resolve file path too long exception

Posted by: admin November 30, 2017 Leave a comment

Questions:

I created a app that downloads all document libraries in a SP Site , but at one point it giving me this error (I tried looking at google but couldn;t find anything, now if anyone knows any trick to solve this problem please respond otherwise thanks for looking at it)

System.IO.PathTooLongException: The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.
at System.IO.Path.NormalizePathFast(String path, Boolean fullCheck)
at System.IO.Path.GetFullPathInternal(String path)
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
at System.IO.File.Create(String path)

it reaches the limit for string, Code is given below,

#region Downloading Schemes

    private void btnDownload_Click(object sender, EventArgs e)
    {
        TreeNode currentNode = tvWebs.SelectedNode;
        SPObjectData objectData = (SPObjectData)currentNode.Tag;
        try
        {
            CreateLoggingFile();
            using (SPWeb TopLevelWeb = objectData.Web)
            {
                if(TopLevelWeb != null)
                    dwnEachWeb(TopLevelWeb, TopLevelWeb.Title, tbDirectory.Text);
            }
        }
        catch (Exception ex)
        {
            Trace.WriteLine(string.Format("Exception caught when tried to pass TopLevelWeb:{1}, Title = {2}, object data to (dwnEachWeb_method), Exception: {0}", ex.ToString(), objectData.Web, objectData.Title));
        }
        finally
        {
            CloseLoggingFile();
        }
    }

    private void dwnEachWeb(SPWeb TopLevelWeb, string FolderName, string CurrentDirectory)
    {
        if (TopLevelWeb != null)
        {
            if (TopLevelWeb.Webs != null)
            {
                CurrentDirectory = CurrentDirectory + "\" + TopLevelWeb.Title;
                CreateFolder(CurrentDirectory);
                foreach (SPWeb ChildWeb in TopLevelWeb.Webs)
                {

                    dwnEachWeb(ChildWeb, ChildWeb.Title, CurrentDirectory);
                    ChildWeb.Dispose();
                }
                dwnEachList(TopLevelWeb, CurrentDirectory);
                //dwnEachList(TopLevelWeb, FolderName, CurrentDirectory);
            }
        }
    }

    private void dwnEachList(SPWeb oWeb, string CurrentDirectory)
    {
        foreach (SPList oList in oWeb.Lists)
        {
            if (oList is SPDocumentLibrary && !oList.Hidden)
            {
                dwnEachFile(oList.RootFolder, CurrentDirectory);
            }
        }
    }

    private void dwnEachFile(SPFolder oFolder, string CurrentDirectory)
    {
        if (oFolder.Files.Count != 0)
        {
            CurrentDirectory = CurrentDirectory + "\" + oFolder.Name;
            CreateFolder(CurrentDirectory);
            foreach (SPFile ofile in oFolder.Files)
            {
                if (CreateDirectoryStructure(CurrentDirectory, ofile.Url))
                {
                    var filepath = System.IO.Path.Combine(CurrentDirectory, ofile.Url);
                    byte[] binFile = ofile.OpenBinary();
                    System.IO.FileStream fstream = System.IO.File.Create(filepath);
                    fstream.Write(binFile, 0, binFile.Length);
                    fstream.Close();
                }
            }
        }
    }

    //creating directory where files will be download        
    private bool CreateDirectoryStructure(string baseFolder, string filepath)
    {
        if (!Directory.Exists(baseFolder)) return false;

        var paths = filepath.Split('/');

        for (var i = 0; i < paths.Length - 1; i++)
        {
            baseFolder = System.IO.Path.Combine(baseFolder, paths[i]);
            Directory.CreateDirectory(baseFolder);
        }
        return true;
    }

    //creating folders
    private bool CreateFolder(string CurrentDirectory)
    {
        if (!Directory.Exists(CurrentDirectory))
        {
            Directory.CreateDirectory(CurrentDirectory);
        }
        return true;
    }

    //shorting string

    #endregion
Answers:

As the cause of the error is obvious, here’s some information that should help you solve the problem:

See this MS article about Naming Files, Paths, and Namespaces

Here’s a quote from the link:

Maximum Path Length Limitation In the Windows API (with some exceptions discussed in the following paragraphs), the maximum length
for a path is MAX_PATH, which is defined as 260 characters. A local
path is structured in the following order: drive letter, colon,
backslash, name components separated by backslashes, and a terminating
null character. For example, the maximum path on drive D is “D:\some
256-character path string<NUL>” where “<NUL>” represents the invisible
terminating null character for the current system codepage. (The
characters < > are used here for visual clarity and cannot be part of
a valid path string.)

And a few workarounds (taken from the comments):

There are ways to solve the various problems. The basic idea of the solutions listed below is always the same: Reduce the path-length in order to have path-length + name-length < MAX_PATH. You may:

  • Share a subfolder
  • Use the commandline to assign a drive letter by means of SUBST
  • Use AddConnection under VB to assign a drive letter to a path
Questions:
Answers:

There’s a library called Zeta Long Paths that provides a .NET API to work with long paths.

Here’s a good article that covers this issue for both .NET and PowerShell: “.NET, PowerShell Path too Long Exception and a .NET PowerShell Robocopy Clone

Questions:
Answers:

On Windows 8.1, using. NET 3.5, I had a similar problem.

Although the name of my file was only 239 characters length when I went to instantiate a FileInfo object with just the file name (without path) occurred an exception of type System. IO.PathTooLongException

2014-01-22 11:10:35 DEBUG LogicalDOCOutlookAddIn.LogicalDOCAddIn - fileName.Length: 239 
2014-01-22 11:10:35 ERROR LogicalDOCOutlookAddIn.LogicalDOCAddIn - Exception in ImportEmail System.IO.PathTooLongException: Percorso e/o nome di file specificato troppo lungo. Il nome di file completo deve contenere meno di 260 caratteri, mentre il nome di directory deve contenere meno di 248 caratteri.
   in System.IO.Path.NormalizePathFast(String path, Boolean fullCheck)
   in System.IO.FileInfo..ctor(String fileName)
   in LogicalDOCOutlookAddIn.LogicalDOCAddIn.GetTempFilePath(String fileName) in C:\Users\alle\Documents\Visual Studio 2010\Projects\MyAddin1Outlook20072010\MyAddin1Outlook20072010\LogicalDOCAddIn.cs:riga 692
   in LogicalDOCOutlookAddIn.LogicalDOCAddIn.ImportEmail(_MailItem mailItem, OutlookConfigXML configXML, Int64 targetFolderID, String SID) in C:\Users\alle\Documents\Visual Studio 2010\Projects\MyAddin1Outlook20072010\MyAddin1Outlook20072010\LogicalDOCAddIn.cs:riga 857
   in LogicalDOCOutlookAddIn.LogicalDOCAddIn.ImportEmails(Explorers explorers, OutlookConfigXML configXML, Int64 targetFolderID, Boolean suppressResultMB) in C:\Users\alle\Documents\Visual Studio 2010\Projects\MyAddin1Outlook20072010\MyAddin1Outlook20072010\LogicalDOCAddIn.cs:riga 99

I resolved the problem trimming the file name to 204 characters (extension included).

Questions:
Answers:

You can create a symbolic link with a shorter directory.
First open command line for example by Shift + RightClick in your desired folder with a shorter path (you may have to run it as administrator).

Then type with relative or absolute paths:

mklink ShortPath\To\YourLinkedSolution C:\Path\To\Your\Solution /D

And then start the Solution from the shorter path. The advantage here is: You don’t have to move anything.

Questions:
Answers:

You can reduce the project name in:

Solution Properties -> Application -> Assembly Name