// hidecon.cpp : released to public domain by author, Dave Hart
// davehart@pobox.com
//
// hidecon runs the program specified on its command line
// forcing it to start up minimized and without GUI activation.
// This is particularly useful with text-mode (console or "DOS"
// programs) being launched by Windows' Task Scheduler which
// you would rather not have appear in front of whatever you
// happen to be doing at the time.  Written to wrap perl.exe,
// a win32 console app, so it can run mrtg script every 5 minutes
// and I can keep my sanity.  This wouldn't be needed if the
// Task Scheduler itself offered options on how to display the
// program in question.
//
// N.B.  This program goes away immediately after launching
// the specified child program.  If you change the code to
// wait for the child to terminate, you should take into
// consideration that this code runs as a win32 GUI process,
// so if you will be blocking to wait for the child to
// complete, don't use the primary thread to do that.  Instead
// enter a GetMessage loop in the primary thread after starting
// another thread to do the wait and then PostThreadMessage to
// let the original thread know to exit the GetMessage loop
// and exit WinMain to finish the process.  Or you could get
// fancy and do it all with one thread and something like
// WaitForMsgAndEvent paired with a PeekMessage loop.  If
// you simply block the initial thread of this GUI process,
// things can hang up as our creator does WaitForInputIdle()
// inside WinExec() or system(), expecting us to be a GUI
// program even though we don't actually create any windows
// or have any capability to receive messages except those
// sent using PostThreadMessage -- nonetheless we need to let
// the GUI system know we are input idle by waiting for the
// (likely nonexistent) incoming messages.
//
// change it (or not!) and copyright (or left!!) it
// to your heart's content :p
//

#include <windows.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>

STARTUPINFO si;
PROCESS_INFORMATION pi;
DWORD dwExitCode;



int CALLBACK WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance,
                     LPSTR pszCommandLine, int nShow)
{
    // for win9x
    SetProcessShutdownParameters(0x101, SHUTDOWN_NORETRY);

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    si.dwFlags = STARTF_USESHOWWINDOW;
    si.wShowWindow = SW_SHOWMINNOACTIVE; // the whole point

    if (! CreateProcess(
              NULL,
              pszCommandLine,
              NULL,  // process security attributes
              NULL,  // thread security attributes
              TRUE,  // bInherhitHandles
              CREATE_DEFAULT_ERROR_MODE,
              NULL,  // environment
              NULL,  // curdir
              &si,
              &pi
              )) {
        return GetLastError();
    }

    CloseHandle(pi.hThread);

    CloseHandle(pi.hProcess);

    return 0;
}