internal static bool DeleteJunction(string junctionPath)
{
bool result = false;
if (!String.IsNullOrEmpty(junctionPath))
{
if (!Platform.IsWindows)
{
// For non-Windows platform, treat it as a file. Just delete it.
try
{
File.Delete(junctionPath);
return true;
}
catch
{
return false;
}
}
using (SafeHandle handle = OpenReparsePoint(junctionPath, FileDesiredAccess.GenericWrite))
{
bool success = false;
int inOutBufferSize = ClrFacade.SizeOf<REPARSE_GUID_DATA_BUFFER>();
IntPtr outBuffer = Marshal.AllocHGlobal(inOutBufferSize);
IntPtr inBuffer = Marshal.AllocHGlobal(inOutBufferSize);
try
{
handle.DangerousAddRef(ref success);
IntPtr dangerousHandle = handle.DangerousGetHandle();
int bytesReturned;
// Do a FSCTL_GET_REPARSE_POINT first because the ReparseTag could be
// IO_REPARSE_TAG_MOUNT_POINT or IO_REPARSE_TAG_SYMLINK.
// Using the wrong one results in mismatched-tag error.
REPARSE_GUID_DATA_BUFFER junctionData = new REPARSE_GUID_DATA_BUFFER();
ClrFacade.StructureToPtr<REPARSE_GUID_DATA_BUFFER>(junctionData, outBuffer, false);
result = DeviceIoControl(dangerousHandle, FSCTL_GET_REPARSE_POINT, IntPtr.Zero, 0,
outBuffer, inOutBufferSize, out bytesReturned, IntPtr.Zero);
if (!result)
{
int lastError = Marshal.GetLastWin32Error();
throw new Win32Exception(lastError);
}
junctionData = ClrFacade.PtrToStructure<REPARSE_GUID_DATA_BUFFER>(outBuffer);
junctionData.ReparseDataLength = 0;
junctionData.DataBuffer = new char[MAX_REPARSE_SIZE];
ClrFacade.StructureToPtr<REPARSE_GUID_DATA_BUFFER>(junctionData, inBuffer, false);
// To delete a reparse point:
// ReparseDataLength must be 0
// inBufferSize must be REPARSE_GUID_DATA_BUFFER_HEADER_SIZE
result = DeviceIoControl(dangerousHandle, FSCTL_DELETE_REPARSE_POINT, inBuffer, REPARSE_GUID_DATA_BUFFER_HEADER_SIZE, IntPtr.Zero, 0, out bytesReturned, IntPtr.Zero);
if (!result)
{
int lastError = Marshal.GetLastWin32Error();
throw new Win32Exception(lastError);
}
}
finally
{
if (success)
{
handle.DangerousRelease();
}
Marshal.FreeHGlobal(outBuffer);
Marshal.FreeHGlobal(inBuffer);
}
}
}
else
{
throw new ArgumentNullException("junctionPath");
}
return result;
}
/// <summary>
/// Gets the target directory from a directory link in Windows Vista.
/// </summary>
/// <param name="directoryInfo">The directory info of this directory
/// link</param>
/// <returns>the target directory, if it was read,
/// otherwise an empty string.</returns>
public static String GetTargetDir(FileSystemInfo directoryInfo)
{
String targetDir = string.Empty;
try
{
// Is it a directory link?
if ((directoryInfo.Attributes
& FileAttributes.ReparsePoint) != 0)
{
// Open the directory link:
IntPtr hFile = CreateFile(directoryInfo.FullName,
0,
0,
IntPtr.Zero,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS |
FILE_FLAG_OPEN_REPARSE_POINT,
IntPtr.Zero);
if (hFile.ToInt32() != INVALID_HANDLE_VALUE)
{
// Allocate a buffer for the reparse point data:
Int32 outBufferSize = Marshal.SizeOf(typeof(REPARSE_GUID_DATA_BUFFER));
IntPtr outBuffer = Marshal.AllocHGlobal(outBufferSize);
try
{
// Read the reparse point data:
Int32 bytesReturned;
Int32 readOK = DeviceIoControl(hFile,
FSCTL_GET_REPARSE_POINT,
IntPtr.Zero,
0,
outBuffer,
outBufferSize,
out bytesReturned,
IntPtr.Zero);
if (readOK != 0)
{
// Get the target directory from the reparse
// point data:
REPARSE_GUID_DATA_BUFFER rgdBuffer =
(REPARSE_GUID_DATA_BUFFER)
Marshal.PtrToStructure
(outBuffer, typeof(REPARSE_GUID_DATA_BUFFER));
targetDir = Encoding.Unicode.GetString
(rgdBuffer.PathBuffer,
rgdBuffer.SubstituteNameOffset,
rgdBuffer.SubstituteNameLength);
if (targetDir.StartsWith
(NonInterpretedPathPrefix))
{
targetDir = targetDir.Substring
(NonInterpretedPathPrefix.Length);
}
}
}
catch (Exception)
{
}
// Free the buffer for the reparse point data:
Marshal.FreeHGlobal(outBuffer);
// Close the directory link:
CloseHandle(hFile);
}
}
}
catch (Exception)
{
}
return(targetDir);
}
/// <summary>
/// Gets the target directory from a directory link in Windows.
/// </summary>
/// <param name="directoryInfo">The directory info of the directory link</param>
/// <returns>The target directory, if link exists, otherwise the FullName</returns>
/// <exception cref="ReparsePointException">Thrown if an error occurs</exception>
public static string GetTargetDirectory(FileSystemInfo directoryInfo)
{
try
{
string targetDir = directoryInfo.FullName;
// Is it a directory link?
if ((directoryInfo.Attributes & FileAttributes.ReparsePoint) == FileAttributes.ReparsePoint)
{
// Open the directory link:
IntPtr hFile = SafeNativeMethods.CreateFile(
directoryInfo.FullName,
0,
0,
IntPtr.Zero,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT,
IntPtr.Zero);
if (hFile.ToInt32() != INVALID_HANDLE_VALUE)
{
// Allocate a buffer for the reparse point data:
int outBufferSize = Marshal.SizeOf(typeof(REPARSE_GUID_DATA_BUFFER));
IntPtr outBuffer = Marshal.AllocHGlobal(outBufferSize);
try
{
// Read the reparse point data:
int bytesReturned;
int readOK = SafeNativeMethods.DeviceIoControl(
hFile,
FSCTL_GET_REPARSE_POINT,
IntPtr.Zero,
0,
outBuffer,
outBufferSize,
out bytesReturned,
IntPtr.Zero);
if (readOK != 0)
{
// Get the target directory from the reparse point data:
REPARSE_GUID_DATA_BUFFER rgdBuffer = (REPARSE_GUID_DATA_BUFFER)Marshal.PtrToStructure(outBuffer, typeof(REPARSE_GUID_DATA_BUFFER));
targetDir = Encoding.Unicode.GetString(
rgdBuffer.PathBuffer,
rgdBuffer.SubstituteNameOffset,
rgdBuffer.SubstituteNameLength);
if (targetDir.StartsWith(NonInterpretedPathPrefix, StringComparison.OrdinalIgnoreCase))
{
targetDir = targetDir.Substring(NonInterpretedPathPrefix.Length);
}
}
}
catch (Exception ex)
{
throw new ReparsePointException("Failed to access ReparsePoint.", ex);
}
finally
{
// Free the buffer for the reparse point data:
Marshal.FreeHGlobal(outBuffer);
// Close the directory link:
SafeNativeMethods.CloseHandle(hFile);
}
}
}
return(targetDir);
}
catch (Exception ex)
{
throw new ReparsePointException("Failed to access ReparsePoint.", ex);
}
}
