How can I get a list of all open named pipes in Windows and avoiding possible exceptions?

Question

Getting the list of named pipes is in ideal case pretty simple and can be found here: How can I get a list of all open named pipes in Windows?

But mentioned solution

var namedPipes = Directory.GetFiles(@"\\.\pipe\");

has occasionally unpredictable results. One of them was mentioned in the link above (Invalid character in path exception). Today I met my own exception:

ArgumentException "The second path fragment must not be a drive or UNC name. Parameter name: path2".

Question is whether there is any really working solution in .net to get the list of all opened named pipes? Thanks

Answer 1

I dug into Directory class source code and found an inspiration. Here is a working solution which gives you list of all opened named pipes. My result does not contain \\.\pipe\ prefix as it can be seen in result of Directory.GetFiles. I tested my solution on WinXp SP3, Win 7, Win 8.1.

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    struct WIN32_FIND_DATA
    {
        public uint dwFileAttributes;
        public System.Runtime.InteropServices.ComTypes.FILETIME ftCreationTime;
        public System.Runtime.InteropServices.ComTypes.FILETIME ftLastAccessTime;
        public System.Runtime.InteropServices.ComTypes.FILETIME ftLastWriteTime;
        public uint nFileSizeHigh;
        public uint nFileSizeLow;
        public uint dwReserved0;
        public uint dwReserved1;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        public string cFileName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]
        public string cAlternateFileName;
    }

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    static extern IntPtr FindFirstFile(string lpFileName, out WIN32_FIND_DATA lpFindFileData);


    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATA
       lpFindFileData);

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool FindClose(IntPtr hFindFile);

    private static void Main(string[] args)
    {
        var namedPipes = new List<string>();
        WIN32_FIND_DATA lpFindFileData;

        var ptr = FindFirstFile(@"\\.\pipe\*", out lpFindFileData);
        namedPipes.Add(lpFindFileData.cFileName);
        while (FindNextFile(ptr, out lpFindFileData))
        {
            namedPipes.Add(lpFindFileData.cFileName);
        }
        FindClose(ptr);

        namedPipes.Sort();

        foreach (var v in namedPipes)
            Console.WriteLine(v);

        Console.ReadLine();
     }