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, __ms_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(GetConsoleOutputCP(), 0, msg_buffer, wlen,
  51             NULL, 0, NULL, NULL);
  52         msgA = HeapAlloc(GetProcessHeap(), 0, len);
  53         if (!msgA)
  54             return 0;
  55
  56         WideCharToMultiByte(GetConsoleOutputCP(), 0, msg_buffer, wlen, msgA, len,
  57             NULL, NULL);
  58         WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), msgA, len, &count, FALSE);
  59         HeapFree(GetProcessHeap(), 0, msgA);
  60     }
  61
  62     return count;
  63 }
  64
  65 static int WINAPIV hostname_printfW(const WCHAR *msg, ...)
  66 {
  67     __ms_va_list va_args;
  68     int len;
  69
  70     __ms_va_start(va_args, msg);
  71     len = hostname_vprintfW(msg, va_args);
  72     __ms_va_end(va_args);
  73
  74     return len;
  75 }
  76
  77 static int WINAPIV hostname_message_printfW(int msg, ...)
  78 {
  79     __ms_va_list va_args;
  80     WCHAR msg_buffer[8192];
  81     int len;
  82
  83     LoadStringW(GetModuleHandleW(NULL), msg, msg_buffer, ARRAY_SIZE(msg_buffer));
  84
  85     __ms_va_start(va_args, msg);
  86     len = hostname_vprintfW(msg_buffer, va_args);
  87     __ms_va_end(va_args);
  88
  89     return len;
  90 }
  91
  92 static int hostname_message(int msg)
  93 {
  94     static const WCHAR formatW[] = {'%','s',0};
  95     WCHAR msg_buffer[8192];
  96
  97     LoadStringW(GetModuleHandleW(NULL), msg, msg_buffer, ARRAY_SIZE(msg_buffer));
  98
  99     return hostname_printfW(formatW, msg_buffer);
 100 }
 101
 102 static int display_computer_name(void)
 103 {
 104     static const WCHAR fmtW[] = {'%','s','\r','\n',0};
 105
 106     WCHAR name[MAX_COMPUTERNAME_LENGTH + 1];
 107     DWORD size = ARRAY_SIZE(name);
 108     BOOL ret;
 109
 110     ret = GetComputerNameW(name, &size);
 111     if (!ret)
 112     {
 113         hostname_message_printfW(STRING_CANNOT_GET_HOSTNAME, GetLastError());
 114         return 1;
 115     }
 116
 117     hostname_printfW(fmtW, name);
 118     return 0;
 119 }
 120
 121 int __cdecl wmain(int argc, WCHAR *argv[])
 122 {
 123     if (argc > 1)
 124     {
 125         static const WCHAR slashHelpW[] = {'/','?',0};
 126
 127         unsigned int i;
 128
 129         if (!wcsncmp(argv[1], slashHelpW, ARRAY_SIZE(slashHelpW) - 1))
 130         {
 131             hostname_message(STRING_USAGE);
 132             return 1;
 133         }
 134
 135         for (i = 1; i < argc; i++)
 136         {
 137             if (argv[i][0] == '-')
 138             {
 139                 switch (argv[i][1])
 140                 {
 141                     case 's':
 142                         /* Ignore the option and continue processing. */
 143                         break;
 144                     case '?':
 145                         hostname_message(STRING_USAGE);
 146                         return 1;
 147                     default:
 148                         hostname_message_printfW(STRING_INVALID_OPTION, argv[i][1]);
 149                         hostname_message(STRING_USAGE);
 150                         return 1;
 151                 }
 152             }
 153             else
 154             {
 155                 hostname_message(STRING_CANNOT_SET_HOSTNAME);
 156                 hostname_message(STRING_USAGE);
 157                 return 1;
 158             }
 159         }
 160     }
 161
 162     return display_computer_name();
 163 }