检查文件是否是真实的还是符号链接

问题描述

有没有办法告诉使用C＃如果文件是真实的还是符号链接？

Is there a way to tell using C# if a file is real or a symbolic link?

我已经通过MSDN文档W32挖（http://msdn.microsoft.com/en-us/library/aa364232(VS.85).aspx),而找不到选中此事情。我使用CreateSymbolicLink从这里，和它的正常工作。

I've dug through the MSDN W32 docs (http://msdn.microsoft.com/en-us/library/aa364232(VS.85).aspx), and can't find anything for checking this. I'm using CreateSymbolicLink from here, and it's working fine.

推荐答案

我有一些的符号链接，让您可以：

I have some source code for symlinks posted on my blog that will allow you to:

• 创建符号链接


• 检查路径是否是一个符号链接


• 检索符号链接的目标

它也包含了NUnit测试的情况下，您可能希望延长。

It also contains NUnit test cases, that you may wish to extend.

肉香位的是：

private static SafeFileHandle getFileHandle(string path)
{
    return CreateFile(path, genericReadAccess, shareModeAll, IntPtr.Zero, openExisting,
        fileFlagsForOpenReparsePointAndBackupSemantics, IntPtr.Zero);
}

public static string GetTarget(string path)
{
    SymbolicLinkReparseData reparseDataBuffer;

    using (SafeFileHandle fileHandle = getFileHandle(path))
    {
        if (fileHandle.IsInvalid)
        {
            Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
        }

        int outBufferSize = Marshal.SizeOf(typeof(SymbolicLinkReparseData));
        IntPtr outBuffer = IntPtr.Zero;
        try
        {
            outBuffer = Marshal.AllocHGlobal(outBufferSize);
            int bytesReturned;
            bool success = DeviceIoControl(
                fileHandle.DangerousGetHandle(), ioctlCommandGetReparsePoint, IntPtr.Zero, 0,
                outBuffer, outBufferSize, out bytesReturned, IntPtr.Zero);

            fileHandle.Close();

            if (!success)
            {
                if (((uint)Marshal.GetHRForLastWin32Error()) == pathNotAReparsePointError)
                {
                    return null;
                }
                Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
            }

            reparseDataBuffer = (SymbolicLinkReparseData)Marshal.PtrToStructure(
                outBuffer, typeof(SymbolicLinkReparseData));
        }
        finally
        {
            Marshal.FreeHGlobal(outBuffer);
        }
    }
    if (reparseDataBuffer.ReparseTag != symLinkTag)
    {
        return null;
    }

    string target = Encoding.Unicode.GetString(reparseDataBuffer.PathBuffer,
        reparseDataBuffer.PrintNameOffset, reparseDataBuffer.PrintNameLength);

    return target;
}

这就是：

• 使用


• 的DeviceIoControl（） 以获得重分析点数据（注：这可能是一个结点）


• 查看rel=\"nofollow\">返回href=\"http://msdn.microsoft.com/en-us/library/windows/hardware/ff552012%28v=vs.85%29.aspx\"的检查。该会告诉你，如果它是一个结点或符号链接。这可能是所有你想做的事。

• Open the file with CreateFile()
• Call DeviceIoControl() to get the reparse point data (NOTE: it could be a junction point!)
• Check out the returned data structure to inspect. The reparse tag will tell you if it is a junction point or symbolic link. This may be all you want to do.

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