c# - 「mklink/J」に相当するC＃は何ですか？

Question

.batスクリプトでウィンドウにシンボリックリンクを作成する方法を知っています。

mklink /J <LinkPath> <OriginalResourcePath>

C＃で同じことを行う方法は？

私はC＃の初心者であり、おそらく適切な用語を使用していないため、グーグルに満足していません。誰でも使用するAPIを指定できますか？

Answer 1

警告：シンボリックリンクを参照していると同時に、ジャンクションを作成するために使用される/ Jスイッチを参照しているため、質問は明確ではありません。この回答は、「c＃でシンボリックリンクを作成する方法」（/ Jなし）に言及しています。代わりに、ジャンクションの作成については、.NETで、シンボリックリンクではなくNTFSでジャンクションを作成するにはどうすればよいですか？を参照してください。。

シンボリックリンクを作成する方法は次のとおりです。

using System.Runtime.InteropServices;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        [DllImport("kernel32.dll")]
        static extern bool CreateSymbolicLink(
        string lpSymlinkFileName, string lpTargetFileName, SymbolicLink dwFlags);

        enum SymbolicLink
        {
            File = 0,
            Directory = 1
        }

        static void Main(string[] args)
        {
            string symbolicLink = @"c:\bar.txt";
            string fileName = @"c:\temp\foo.txt";

            using (var writer = File.CreateText(fileName))
            {
                writer.WriteLine("Hello World");
            }

            CreateSymbolicLink(symbolicLink, fileName, SymbolicLink.File);
        }
    }
}

これにより、C：ドライブにbar.txtというシンボリックリンクファイルが作成され、C：\tempディレクトリに保存されているfoo.txtテキストファイルにリンクします。

Answer 2

ジャンクションを作成するためのPInvoke署名を持つプロジェクトは次のとおりです：http：//www.codeproject.com/Articles/15633/Manipulating-NTFS-Junction-Points-in-NET。コードは以下にコピーされます：

using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
using Microsoft.Win32.SafeHandles;

namespace Util {
    /// <summary>
    /// Provides access to NTFS junction points in .Net.
    /// </summary>
    public static class JunctionPoint {
        /// <summary>
        /// The file or directory is not a reparse point.
        /// </summary>
        private const int ERROR_NOT_A_REPARSE_POINT = 4390;

        /// <summary>
        /// The reparse point attribute cannot be set because it conflicts with an existing attribute.
        /// </summary>
        private const int ERROR_REPARSE_ATTRIBUTE_CONFLICT = 4391;

        /// <summary>
        /// The data present in the reparse point buffer is invalid.
        /// </summary>
        private const int ERROR_INVALID_REPARSE_DATA = 4392;

        /// <summary>
        /// The tag present in the reparse point buffer is invalid.
        /// </summary>
        private const int ERROR_REPARSE_TAG_INVALID = 4393;

        /// <summary>
        /// There is a mismatch between the tag specified in the request and the tag present in the reparse point.
        /// </summary>
        private const int ERROR_REPARSE_TAG_MISMATCH = 4394;

        /// <summary>
        /// Command to set the reparse point data block.
        /// </summary>
        private const int FSCTL_SET_REPARSE_POINT = 0x000900A4;

        /// <summary>
        /// Command to get the reparse point data block.
        /// </summary>
        private const int FSCTL_GET_REPARSE_POINT = 0x000900A8;

        /// <summary>
        /// Command to delete the reparse point data base.
        /// </summary>
        private const int FSCTL_DELETE_REPARSE_POINT = 0x000900AC;

        /// <summary>
        /// Reparse point tag used to identify mount points and junction points.
        /// </summary>
        private const uint IO_REPARSE_TAG_MOUNT_POINT = 0xA0000003;

        /// <summary>
        /// This prefix indicates to NTFS that the path is to be treated as a non-interpreted
        /// path in the virtual file system.
        /// </summary>
        private const string NonInterpretedPathPrefix = @"\??\";

        [Flags]
        private enum EFileAccess : uint {
            GenericRead = 0x80000000,
            GenericWrite = 0x40000000,
            GenericExecute = 0x20000000,
            GenericAll = 0x10000000,
        }

        [Flags]
        private enum EFileShare : uint {
            None = 0x00000000,
            Read = 0x00000001,
            Write = 0x00000002,
            Delete = 0x00000004,
        }

        private enum ECreationDisposition : uint {
            New = 1,
            CreateAlways = 2,
            OpenExisting = 3,
            OpenAlways = 4,
            TruncateExisting = 5,
        }

        [Flags]
        private enum EFileAttributes : uint {
            Readonly = 0x00000001,
            Hidden = 0x00000002,
            System = 0x00000004,
            Directory = 0x00000010,
            Archive = 0x00000020,
            Device = 0x00000040,
            Normal = 0x00000080,
            Temporary = 0x00000100,
            SparseFile = 0x00000200,
            ReparsePoint = 0x00000400,
            Compressed = 0x00000800,
            Offline = 0x00001000,
            NotContentIndexed = 0x00002000,
            Encrypted = 0x00004000,
            Write_Through = 0x80000000,
            Overlapped = 0x40000000,
            NoBuffering = 0x20000000,
            RandomAccess = 0x10000000,
            SequentialScan = 0x08000000,
            DeleteOnClose = 0x04000000,
            BackupSemantics = 0x02000000,
            PosixSemantics = 0x01000000,
            OpenReparsePoint = 0x00200000,
            OpenNoRecall = 0x00100000,
            FirstPipeInstance = 0x00080000
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct REPARSE_DATA_BUFFER {
            /// <summary>
            /// Reparse point tag. Must be a Microsoft reparse point tag.
            /// </summary>
            public uint ReparseTag;

            /// <summary>
            /// Size, in bytes, of the data after the Reserved member. This can be calculated by:
            /// (4 * sizeof(ushort)) + SubstituteNameLength + PrintNameLength + 
            /// (namesAreNullTerminated ? 2 * sizeof(char) : 0);
            /// </summary>
            public ushort ReparseDataLength;

            /// <summary>
            /// Reserved; do not use. 
            /// </summary>
            public ushort Reserved;

            /// <summary>
            /// Offset, in bytes, of the substitute name string in the PathBuffer array.
            /// </summary>
            public ushort SubstituteNameOffset;

            /// <summary>
            /// Length, in bytes, of the substitute name string. If this string is null-terminated,
            /// SubstituteNameLength does not include space for the null character.
            /// </summary>
            public ushort SubstituteNameLength;

            /// <summary>
            /// Offset, in bytes, of the print name string in the PathBuffer array.
            /// </summary>
            public ushort PrintNameOffset;

            /// <summary>
            /// Length, in bytes, of the print name string. If this string is null-terminated,
            /// PrintNameLength does not include space for the null character. 
            /// </summary>
            public ushort PrintNameLength;

            /// <summary>
            /// A buffer containing the unicode-encoded path string. The path string contains
            /// the substitute name string and print name string.
            /// </summary>
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x3FF0)]
            public byte[] PathBuffer;
        }

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern bool DeviceIoControl(IntPtr hDevice, uint dwIoControlCode,
            IntPtr InBuffer, int nInBufferSize,
            IntPtr OutBuffer, int nOutBufferSize,
            out int pBytesReturned, IntPtr lpOverlapped);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern IntPtr CreateFile(
            string lpFileName,
            EFileAccess dwDesiredAccess,
            EFileShare dwShareMode,
            IntPtr lpSecurityAttributes,
            ECreationDisposition dwCreationDisposition,
            EFileAttributes dwFlagsAndAttributes,
            IntPtr hTemplateFile);

        /// <summary>
        /// Creates a junction point from the specified directory to the specified target directory.
        /// </summary>
        /// <remarks>
        /// Only works on NTFS.
        /// </remarks>
        /// <param name="targetDir">The target directory to create</param>
        /// <param name="sourceDir">The source directory to alias</param>
        /// <param name="overwrite">If true overwrites an existing reparse point or empty directory</param>
        /// <exception cref="IOException">Thrown when the junction point could not be created or when
        /// an existing directory was found and <paramref name="overwrite" /> if false</exception>
        public static void Create(string sourceDir, string targetDir, bool overwrite) {
            sourceDir = Path.GetFullPath(sourceDir);

            if (!Directory.Exists(sourceDir))
                throw new IOException($"Source path does not exist or is not a directory.");

            if (Directory.Exists(targetDir))
                throw new IOException($"Directory '{targetDir}' already exists.");

            Directory.CreateDirectory(targetDir);

            using (SafeFileHandle handle = OpenReparsePoint(targetDir, EFileAccess.GenericWrite)) {
                byte[] sourceDirBytes = Encoding.Unicode.GetBytes(NonInterpretedPathPrefix + Path.GetFullPath(sourceDir));

                REPARSE_DATA_BUFFER reparseDataBuffer = new REPARSE_DATA_BUFFER();

                reparseDataBuffer.ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
                reparseDataBuffer.ReparseDataLength = (ushort)(sourceDirBytes.Length + 12);
                reparseDataBuffer.SubstituteNameOffset = 0;
                reparseDataBuffer.SubstituteNameLength = (ushort)sourceDirBytes.Length;
                reparseDataBuffer.PrintNameOffset = (ushort)(sourceDirBytes.Length + 2);
                reparseDataBuffer.PrintNameLength = 0;
                reparseDataBuffer.PathBuffer = new byte[0x3ff0];
                Array.Copy(sourceDirBytes, reparseDataBuffer.PathBuffer, sourceDirBytes.Length);

                int inBufferSize = Marshal.SizeOf(reparseDataBuffer);
                IntPtr inBuffer = Marshal.AllocHGlobal(inBufferSize);

                try {
                    Marshal.StructureToPtr(reparseDataBuffer, inBuffer, false);

                    int bytesReturned;
                    bool result = DeviceIoControl(handle.DangerousGetHandle(), FSCTL_SET_REPARSE_POINT,
                        inBuffer, sourceDirBytes.Length + 20, IntPtr.Zero, 0, out bytesReturned, IntPtr.Zero);

                    if (!result)
                        ThrowLastWin32Error($"Unable to create junction point '{sourceDir}' -> '{targetDir}'.");
                } finally {
                    Marshal.FreeHGlobal(inBuffer);
                }
            }
        }

        /// <summary>
        /// Deletes a junction point at the specified source directory along with the directory itself.
        /// Does nothing if the junction point does not exist.
        /// </summary>
        /// <remarks>
        /// Only works on NTFS.
        /// </remarks>
        /// <param name="junctionPoint">The junction point path</param>
        public static void Delete(string junctionPoint) {
            if (!Directory.Exists(junctionPoint)) {
                if (File.Exists(junctionPoint))
                    throw new IOException("Path is not a junction point.");

                return;
            }

            using (SafeFileHandle handle = OpenReparsePoint(junctionPoint, EFileAccess.GenericWrite)) {
                REPARSE_DATA_BUFFER reparseDataBuffer = new REPARSE_DATA_BUFFER();

                reparseDataBuffer.ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
                reparseDataBuffer.ReparseDataLength = 0;
                reparseDataBuffer.PathBuffer = new byte[0x3ff0];

                int inBufferSize = Marshal.SizeOf(reparseDataBuffer);
                IntPtr inBuffer = Marshal.AllocHGlobal(inBufferSize);
                try {
                    Marshal.StructureToPtr(reparseDataBuffer, inBuffer, false);

                    int bytesReturned;
                    bool result = DeviceIoControl(handle.DangerousGetHandle(), FSCTL_DELETE_REPARSE_POINT,
                        inBuffer, 8, IntPtr.Zero, 0, out bytesReturned, IntPtr.Zero);

                    if (!result)
                        ThrowLastWin32Error("Unable to delete junction point.");
                } finally {
                    Marshal.FreeHGlobal(inBuffer);
                }

                try {
                    Directory.Delete(junctionPoint);
                } catch (IOException ex) {
                    throw new IOException("Unable to delete junction point.", ex);
                }
            }
        }

        /// <summary>
        /// Determines whether the specified path exists and refers to a junction point.
        /// </summary>
        /// <param name="path">The junction point path</param>
        /// <returns>True if the specified path represents a junction point</returns>
        /// <exception cref="IOException">Thrown if the specified path is invalid
        /// or some other error occurs</exception>
        public static bool Exists(string path) {
            if (!Directory.Exists(path))
                return false;

            using (SafeFileHandle handle = OpenReparsePoint(path, EFileAccess.GenericRead)) {
                string target = InternalGetTarget(handle);
                return target != null;
            }
        }

        /// <summary>
        /// Gets the target of the specified junction point.
        /// </summary>
        /// <remarks>
        /// Only works on NTFS.
        /// </remarks>
        /// <param name="junctionPoint">The junction point path</param>
        /// <returns>The target of the junction point</returns>
        /// <exception cref="IOException">Thrown when the specified path does not
        /// exist, is invalid, is not a junction point, or some other error occurs</exception>
        public static string GetTarget(string junctionPoint) {
            using (SafeFileHandle handle = OpenReparsePoint(junctionPoint, EFileAccess.GenericRead)) {
                string target = InternalGetTarget(handle);
                if (target == null)
                    throw new IOException("Path is not a junction point.");

                return target;
            }
        }

        private static string InternalGetTarget(SafeFileHandle handle) {
            int outBufferSize = Marshal.SizeOf(typeof(REPARSE_DATA_BUFFER));
            IntPtr outBuffer = Marshal.AllocHGlobal(outBufferSize);

            try {
                int bytesReturned;
                bool result = DeviceIoControl(handle.DangerousGetHandle(), FSCTL_GET_REPARSE_POINT,
                    IntPtr.Zero, 0, outBuffer, outBufferSize, out bytesReturned, IntPtr.Zero);

                if (!result) {
                    int error = Marshal.GetLastWin32Error();
                    if (error == ERROR_NOT_A_REPARSE_POINT)
                        return null;

                    ThrowLastWin32Error("Unable to get information about junction point.");
                }

                REPARSE_DATA_BUFFER reparseDataBuffer = (REPARSE_DATA_BUFFER)
                    Marshal.PtrToStructure(outBuffer, typeof(REPARSE_DATA_BUFFER));

                if (reparseDataBuffer.ReparseTag != IO_REPARSE_TAG_MOUNT_POINT)
                    return null;

                string targetDir = Encoding.Unicode.GetString(reparseDataBuffer.PathBuffer,
                    reparseDataBuffer.SubstituteNameOffset, reparseDataBuffer.SubstituteNameLength);

                if (targetDir.StartsWith(NonInterpretedPathPrefix))
                    targetDir = targetDir.Substring(NonInterpretedPathPrefix.Length);

                return targetDir;
            } finally {
                Marshal.FreeHGlobal(outBuffer);
            }
        }

        private static SafeFileHandle OpenReparsePoint(string reparsePoint, EFileAccess accessMode) {
            SafeFileHandle reparsePointHandle = new SafeFileHandle(CreateFile(reparsePoint, accessMode,
                EFileShare.Read | EFileShare.Write | EFileShare.Delete,
                IntPtr.Zero, ECreationDisposition.OpenExisting,
                EFileAttributes.BackupSemantics | EFileAttributes.OpenReparsePoint, IntPtr.Zero), true);

            if (Marshal.GetLastWin32Error() != 0)
                ThrowLastWin32Error("Unable to open reparse point.");

            return reparsePointHandle;
        }

        private static void ThrowLastWin32Error(string message) {
            throw new IOException(message, Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error()));
        }
    }
}

Answer 3

mklinkを使用する別の方法。mklinkは内部コマンドであることが判明したため、これを呼び出すにはcmd.exeが必要です。

var psi=new ProcessStartInfo("cmd.exe"," /C mklink \""+link_name+"\" \""+ target_name + "\"");
psi.CreateNoWindow = true;
psi.UseShellExecute = false;
Process.Start(psi).WaitForExit();

必要に応じて/Jや/dなどを追加できます。

ref：コマンドプロンプトコマンドの実行