os_win32/wtssendmsg.c

   1 /*
   2  * WTSSendMessage() command line tool
   3  *
   4  * Home page of code is: http://www.smartmontools.org
   5  *
   6  * Copyright (C) 2012 Christian Franke
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #define WINVER 0x0500
  12 #define _WIN32_WINNT WINVER
  13
  14 char svnid[] = "$Id: wtssendmsg.c 4760 2018-08-19 18:45:53Z chrfranke $";
  15
  16 #include <stdio.h>
  17 #include <string.h>
  18
  19 #define WIN32_LEAN_AND_MEAN
  20 #include <windows.h>
  21 #include <wtsapi32.h>
  22
  23
  24 static int usage()
  25 {
  26   printf("wtssendmsg $Revision: 4760 $ - Display a message box on client desktops\n"
  27          "Copyright (C) 2012 Christian Franke, smartmontools.org\n\n"
  28          "Usage: wtssendmsg [-cas] [-v] [\"Caption\"] \"Message\"|-\n"
  29          "       wtssendmsg -v\n\n"
  30          "  -c    Console session [default]\n"
  31          "  -a    Active sessions\n"
  32          "  -s    Connected sessions\n"
  33          "  -v    List sessions\n"
  34   );
  35   return 1;
  36 }
  37
  38 int main(int argc, const char **argv)
  39 {
  40   int mode = 0, verbose = 0, status = 0, i;
  41   const char * message = 0, * caption = "";
  42   char msgbuf[1024];
  43   WTS_SESSION_INFOA * sessions; DWORD count;
  44
  45   for (i = 1; i < argc && argv[i][0] == '-' && argv[i][1]; i++) {
  46     int j;
  47     for (j = 1; argv[i][j]; j++)
  48       switch (argv[i][j]) {
  49       case 'c': mode = 0; break;
  50       case 'a': mode = 1; break;
  51       case 's': mode = 2; break;
  52       case 'v': verbose = 1; break;
  53       default: return usage();
  54     }
  55   }
  56
  57   if (i < argc) {
  58     if (i+1 < argc)
  59       caption = argv[i++];
  60
  61     message = argv[i++];
  62     if (i < argc)
  63       return usage();
  64
  65     if (!strcmp(message, "-")) {
  66       // Read message from stdin
  67       i = fread(msgbuf, 1, sizeof(msgbuf)-1, stdin);
  68       if (i < 0) {
  69         perror("stdin");
  70         return 1;
  71       }
  72       msgbuf[i] = 0;
  73       message = msgbuf;
  74     }
  75   }
  76   else {
  77       if (!verbose)
  78         return usage();
  79   }
  80
  81   // Get session list
  82   if (!WTSEnumerateSessionsA(WTS_CURRENT_SERVER_HANDLE, 0, 1, &sessions, &count)) {
  83     fprintf(stderr, "WTSEnumerateSessions() failed\n");
  84     return 1;
  85   }
  86
  87   for (i = 0; i < (int)count; i++) {
  88
  89     if (verbose) {
  90       printf("Session %d (\"%s\", State=%d)%s",
  91              i, sessions[i].pWinStationName, sessions[i].State,
  92              (!message ? "\n" : ": "));
  93       if (!message)
  94         continue; // List sessions only
  95       fflush(stdout);
  96     }
  97
  98     if (   !strcmpi(sessions[i].pWinStationName, "Console")
  99         || (mode >= 1 && sessions[i].State == WTSActive)
 100         || (mode >= 2 && sessions[i].State == WTSConnected)) {
 101
 102       // Send Message, don't wait for OK button
 103       DWORD result;
 104       if (WTSSendMessageA(WTS_CURRENT_SERVER_HANDLE, sessions[i].SessionId,
 105           (char *)caption, strlen(caption),
 106           (char *)message, strlen(message),
 107           MB_OK|MB_ICONEXCLAMATION, 0 /*Timeout*/,
 108           &result, FALSE /*!Wait*/)) {
 109         if (verbose)
 110           printf("message sent\n");
 111       }
 112       else {
 113         status = 1;
 114         if (verbose)
 115           printf("WTSSendMessage() failed with error=%d\n", (int)GetLastError());
 116         else
 117           fprintf(stderr, "Session %d (\"%s\", State=%d): WTSSendMessage() failed with error=%d\n",
 118                   i, sessions[i].pWinStationName, sessions[i].State, (int)GetLastError());
 119       }
 120     }
 121     else {
 122       if (verbose)
 123         printf("ignored\n");
 124     }
 125   }
 126
 127   WTSFreeMemory(sessions);
 128
 129   return status;
 130 }