src/System.Private.CoreLib/shared/Interop/Windows/Kernel32/Interop.GetComputerName.cs


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Runtime.InteropServices;

internal partial class Interop
{
    internal partial class Kernel32
    {
        [DllImport(Libraries.Kernel32, CharSet = CharSet.Unicode, EntryPoint = "GetComputerNameW")]
        private static extern unsafe int GetComputerName(ref char lpBuffer, ref uint nSize);

        // maximum length of the NETBIOS name (not including NULL)
        private const int MAX_COMPUTERNAME_LENGTH = 15;

        internal static unsafe string GetComputerName()
        {
            Span<char> buffer = stackalloc char[MAX_COMPUTERNAME_LENGTH + 1];
            uint length = (uint)buffer.Length;

            return GetComputerName(ref MemoryMarshal.GetReference(buffer), ref length) != 0 ?
                buffer.Slice(0, (int)length).ToString() :
                null;
        }
    }
}