Re: WinExec() and CreateProcess()
On Mon, 16 Aug 2010 14:23:22 -0700 (PDT), wang <king_wwang@yahoo.de>
wrote:
On 16 Aug., 03:20, Joseph M. Newcomer <newco...@flounder.com> wrote:
See below...
On Thu, 12 Aug 2010 14:06:25 -0700 (PDT), wang <king_ww...@yahoo.de> wrote:
Hi all,
I've tested WinExec() as follows:
WinExec(cmd, SW_HIDE);
****
And what part of the "this function is obsolete" did you fail to understand? ?Why would
you even CONSIDER this as a means of launching a program?
I understand it fairly well, therefore I asked how to use
"CreateProcess()" because I don't want to use "WinExec()" anymore. I
took this only to examplify what effect I want to achieve with
"CreateProcess()".
WinExec is DEAD and must not be used!
******
The behaviour of the program during running is satisfactory. But a
test with CreateProcess() failed. Since WinExec() is a macro
****
Why do you think it is a macro? ?What led you to this conclusion? ?There is nothing which
even suggests this.
Quote from Davis Chapman "Teach yourself VC++ in 21 Days", Chapter 2,
near the end of the chapter (just above the chapter summary):
The WinExec function is an obsolete Windows function. You really
should use
the CreateProcess function instead. However, the CreateProcess
function has a
number of arguments that are difficult to understand this early in
programming
using Visual C++. The WinExec function is still available and is
implemented
as a macro that calls the CreateProcess function. This allows you to
use the much simpler WinExec function to run another application while
still
using the function that Windows wants you to use.
****>which
calls CreateProcess(), what parameter list should be used with
CreateProcess() to get the same effect as WinExec(cmd, SW_HIDE)? Many
thanks in advance!
*****
Since ?you don't define what is "correct" behavior and you do not state what is wrong with
the observed ?behavior, there is no way to answer this question. ?You did not say how you
call CreateProcess. ?There is nothing here that could possible enable anyone to answer
this question!
I asked what parameter list should be used with CreateProcess() to get
the same effect as WinExec(cmd, SW_HIDE). I think I've defined this
way what "correct" behaviour I expect is (namely, as WinExec(cmd,
SW_HIDE) does).
Joe likes to write paragraphs about how screwed up your code is or how
you're doing it all wrong but seldom directly answers a question like
yours.
A better phrasing of the question would be, "How do I make
CreateProcess do what WinExec(cmd, SW_HIDE) does?"
The answer is you have to set up the STARTUPINFO structure before
calling CreateProcess.
Taking a hint from the Microsoft example in the CreateProcess online
help, a minimal Console program to do it might look something like
this:
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
/* Calling this program with "notepad" in the command line
will open a notepad application in the hidden state.
Use TaskManager to close the notepad and this process terminates.
*/
void _tmain( int argc, TCHAR *argv[] )
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
if( argc != 2 )
{
printf("Usage: %s [cmdline]\n", argv[0]);
return;
}
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
ZeroMemory( &pi, sizeof(pi) );
si.dwFlags = STARTF_USESHOWWINDOW; // use wShowWindow information
si.wShowWindow = SW_HIDE;
// Start the child process.
if( !CreateProcess( NULL, // No module name (use command line)
argv[1], // Command line
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
0, // No creation flags
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi )) // Pointer to PROCESS_INFORMATION structure
{
printf( "CreateProcess failed (%d).\n", GetLastError() );
return;
}
// Wait until child process exits.
WaitForSingleObject( pi.hProcess, INFINITE );
// Close process and thread handles.
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
}