programs/hostname/hostname.c

   1 /*
   2  * Hostname display utility
   3  *
   4  * Copyright 2008 Andrew Riedi
   5  * Copyright 2010-2011 Andrew Nguyen
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22 #include <stdarg.h>
  23 #include <stdio.h>
  24 #include <windef.h>
  25 #include <winbase.h>
  26 #include <wincon.h>
  27 #include <winnls.h>
  28 #include <winuser.h>
  29
  30 #include "hostname.h"
  31
  32 static int hostname_vprintfW(const WCHAR *msg, va_list va_args)
  33 {
  34     int wlen;
  35     DWORD count, ret;
  36     WCHAR msg_buffer[8192];
  37
  38     wlen = vswprintf(msg_buffer, ARRAY_SIZE(msg_buffer), msg, va_args);
  39
  40     ret = WriteConsoleW(GetStdHandle(STD_OUTPUT_HANDLE), msg_buffer, wlen, &count, NULL);
  41     if (!ret)
  42     {
  43         DWORD len;
  44         char *msgA;
  45
  46         /* On Windows WriteConsoleW() fails if the output is redirected. So fall
  47          * back to WriteFile(), assuming the console encoding is still the right
  48          * one in that case.
  49          */
  50         len = WideCharToMultiByte(CP_ACP, 0, msg_buffer, wlen,
  51             NULL, 0, NULL, NULL);
  52         msgA = HeapAlloc(GetProcessHeap(), 0, len);
  53         if (!msgA)
  54             return 0;
  55
  56         WideCharToMultiByte(CP_ACP, 0, msg_buffer, wlen, msgA, len, NULL, NULL);
  57         WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), msgA, len, &count, FALSE);
  58         HeapFree(GetProcessHeap(), 0, msgA);
  59     }
  60
  61     return count;
  62 }
  63
  64 static int WINAPIV hostname_printfW(const WCHAR *msg, ...)
  65 {
  66     va_list va_args;
  67     int len;
  68
  69     va_start(va_args, msg);
  70     len = hostname_vprintfW(msg, va_args);
  71     va_end(va_args);
  72
  73     return len;
  74 }
  75
  76 static int WINAPIV hostname_message_printfW(int msg, ...)
  77 {
  78     va_list va_args;
  79     WCHAR msg_buffer[8192];
  80     int len;
  81
  82     LoadStringW(GetModuleHandleW(NULL), msg, msg_buffer, ARRAY_SIZE(msg_buffer));
  83
  84     va_start(va_args, msg);
  85     len = hostname_vprintfW(msg_buffer, va_args);
  86     va_end(va_args);
  87
  88     return len;
  89 }
  90
  91 static int hostname_message(int msg)
  92 {
  93     WCHAR msg_buffer[8192];
  94
  95     LoadStringW(GetModuleHandleW(NULL), msg, msg_buffer, ARRAY_SIZE(msg_buffer));
  96
  97     return hostname_printfW(L"%s", msg_buffer);
  98 }
  99
 100 static int display_computer_name(void)
 101 {
 102     WCHAR name[MAX_COMPUTERNAME_LENGTH + 1];
 103     DWORD size = ARRAY_SIZE(name);
 104     BOOL ret;
 105
 106     ret = GetComputerNameW(name, &size);
 107     if (!ret)
 108     {
 109         hostname_message_printfW(STRING_CANNOT_GET_HOSTNAME, GetLastError());
 110         return 1;
 111     }
 112
 113     hostname_printfW(L"%s\r\n", name);
 114     return 0;
 115 }
 116
 117 int __cdecl wmain(int argc, WCHAR *argv[])
 118 {
 119     if (argc > 1)
 120     {
 121         unsigned int i;
 122
 123         if (!wcsncmp(argv[1], L"/?", ARRAY_SIZE(L"/?") - 1))
 124         {
 125             hostname_message(STRING_USAGE);
 126             return 1;
 127         }
 128
 129         for (i = 1; i < argc; i++)
 130         {
 131             if (argv[i][0] == '-')
 132             {
 133                 switch (argv[i][1])
 134                 {
 135                     case 's':
 136                         /* Ignore the option and continue processing. */
 137                         break;
 138                     case '?':
 139                         hostname_message(STRING_USAGE);
 140                         return 1;
 141                     default:
 142                         hostname_message_printfW(STRING_INVALID_OPTION, argv[i][1]);
 143                         hostname_message(STRING_USAGE);
 144                         return 1;
 145                 }
 146             }
 147             else
 148             {
 149                 hostname_message(STRING_CANNOT_SET_HOSTNAME);
 150                 hostname_message(STRING_USAGE);
 151                 return 1;
 152             }
 153         }
 154     }
 155
 156     return display_computer_name();
 157 }