base/applications/cmdutils/hostname/hostname.c

   1 /*
   2  * PROJECT:     ReactOS Hostname Command
   3  * LICENSE:     LGPL-2.1+ (https://spdx.org/licenses/LGPL-2.1+)
   4  * PURPOSE:     Retrieves the current DNS host name of the computer.
   5  * COPYRIGHT:   Copyright 2005-2019 Emanuele Aliberti (ea@reactos.com)
   6  *              Copyright 2019 Hermes Belusca-Maito
   7  */
   8
   9 #include <stdlib.h>
  10 #include <conio.h>
  11
  12 #include <windef.h>
  13 #include <winbase.h>
  14 #include <winuser.h>
  15
  16 #include "resource.h"
  17
  18 int wmain(int argc, WCHAR* argv[])
  19 {
  20     WCHAR Msg[100];
  21
  22     if (argc == 1)
  23     {
  24         BOOL bSuccess;
  25         WCHAR LocalHostName[256] = L""; // MAX_COMPUTERNAME_LENGTH + 1 for NetBIOS name.
  26         DWORD HostNameSize = _countof(LocalHostName);
  27         PWSTR HostName = LocalHostName;
  28
  29         /* Try to retrieve the host name using the local buffer */
  30         bSuccess = GetComputerNameExW(ComputerNameDnsHostname, HostName, &HostNameSize);
  31         if (!bSuccess && (GetLastError() == ERROR_MORE_DATA))
  32         {
  33             /* Retry with a larger buffer since the local buffer was too small */
  34             HostName = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, HostNameSize * sizeof(WCHAR));
  35             if (HostName)
  36                 bSuccess = GetComputerNameExW(ComputerNameDnsHostname, HostName, &HostNameSize);
  37         }
  38
  39         if (bSuccess)
  40         {
  41             /* Print out the host name */
  42             _cwprintf(L"%s\n", HostName);
  43         }
  44
  45         /* If a larger buffer has been allocated, free it */
  46         if (HostName && (HostName != LocalHostName))
  47             HeapFree(GetProcessHeap(), 0, HostName);
  48
  49         if (!bSuccess)
  50         {
  51             /* Fail in case of error */
  52             LoadStringW(GetModuleHandle(NULL), IDS_ERROR, Msg, _countof(Msg));
  53             _cwprintf(L"%s %lu.\n", Msg, GetLastError());
  54             return 1;
  55         }
  56     }
  57     else
  58     {
  59         if ((wcsicmp(argv[1], L"-s") == 0) || (wcsicmp(argv[1], L"/s") == 0))
  60         {
  61             /* The program doesn't allow the user to set the host name */
  62             LoadStringW(GetModuleHandle(NULL), IDS_NOSET, Msg, _countof(Msg));
  63             _cwprintf(L"%s\n", Msg);
  64             return 1;
  65         }
  66         else
  67         {
  68             /* Let the user know what the program does */
  69             LoadStringW(GetModuleHandle(NULL), IDS_USAGE, Msg, _countof(Msg));
  70             _cwprintf(L"\n%s\n\n", Msg);
  71         }
  72     }
  73
  74     return 0;
  75 }
  76
  77 /* EOF */