Question

I just asked a question earlier today because I wanted to run an executable file that takes parameters from my C++ code and it wasn’t working.

It works now, but I’m still having problems since I thought I was going the right way about this, but it seems like what I want to accomplish can’t be done the way I’m approaching it…

This is my corrected code from my other question:

#include <stdlib.h>
#include <conio.h>

int main (){
    system("\"\"C:\\Users\\Adam\\Desktop\\pdftotext\" -layout \"C:\\Users\\Adam\\Desktop\\week 4.pdf\"\"");
    _getch();
}

which is me running “pdftotext -layout myfile.pdf” as if I was running it from a CMD window.

The thing is, I don’t actually want the cmd to show up since I have a GUI interface on top of it and I want to display a nicer progress bar instead of seeing the windows pop-up for every file I need to parse.

I looked around and either I don’t understand what I’m reading since I’m relatively new to C++, or I just didn’t find what I was looking for. I found that using CreateProcess, I should be able to do this, but after copying some code I found somewhere else, the cmd window pops-up anyway.

I’d like it if someone could give me the name of a function I could use to accomplish something like this or if someone could give some example code for this small case in the code I posted since I’m not sure I understand everything as I should, being new to C++ and all.

Edit: As requested in a comment, the code for CreateProcess that I tried is what I found at this url:

http://www.goffconcepts.com/techarticles/development/cpp/createprocess.html

Which is (with my own parameters that I think should go there):

#include <windows.h>
#include <string>
#include <conio.h>

size_t ExecuteProcess(std::wstring FullPathToExe, std::wstring Parameters, size_t SecondsToWait)
{
    size_t iMyCounter = 0, iReturnVal = 0, iPos = 0;
    DWORD dwExitCode = 0;
    std::wstring sTempStr = L"";

    /* - NOTE - You should check here to see if the exe even exists */

    /* Add a space to the beginning of the Parameters */
    if (Parameters.size() != 0)
    {
        if (Parameters[0] != L' ')
        {
            Parameters.insert(0,L" ");
        }
    }

    /* The first parameter needs to be the exe itself */
    sTempStr = FullPathToExe;
    iPos = sTempStr.find_last_of(L"\\");
    sTempStr.erase(0, iPos +1);
    Parameters = sTempStr.append(Parameters);

     /* CreateProcessW can modify Parameters thus we allocate needed memory */
    wchar_t * pwszParam = new wchar_t[Parameters.size() + 1];
    if (pwszParam == 0)
    {
        return 1;
    }
    const wchar_t* pchrTemp = Parameters.c_str();
    wcscpy_s(pwszParam, Parameters.size() + 1, pchrTemp);

    /* CreateProcess API initialization */
    STARTUPINFOW siStartupInfo;
    PROCESS_INFORMATION piProcessInfo;
    memset(&siStartupInfo, 0, sizeof(siStartupInfo));
    memset(&piProcessInfo, 0, sizeof(piProcessInfo));
    siStartupInfo.cb = sizeof(siStartupInfo);

    if (CreateProcessW(const_cast<LPCWSTR>(FullPathToExe.c_str()),
                            pwszParam, 0, 0, false,
                            CREATE_DEFAULT_ERROR_MODE, 0, 0,
                            &siStartupInfo, &piProcessInfo) != false)
    {
         /* Watch the process. */
        dwExitCode = WaitForSingleObject(piProcessInfo.hProcess, (SecondsToWait * 1000));
    }
    else
    {
        /* CreateProcess failed */
        iReturnVal = GetLastError();
    }

    /* Free memory */
    delete[]pwszParam;
    pwszParam = 0;

    /* Release handles */
    CloseHandle(piProcessInfo.hProcess);
    CloseHandle(piProcessInfo.hThread);

    return iReturnVal;
} 

int main(void){
    ExecuteProcess(L"C:\\Users\\Adam\\Desktop\\pdftotext", L"-layout \"C:\\Users\\Adam\\Desktop\\week 4.pdf\"", 0);
    _getch();
}

I’m a little bit overwhelmed since it uses some things I’ve never used before, but I think I understand the core (keyword: think). It doesn’t solve my problem, though, because the cmd shows up and by retesting it I actually noticed that the cmd doesn’t even run the .exe and doesn’t give me an error message.

I hope this bit of code helps… I didn’t want to look into it further since it seemed like I wasn’t even going in the right direction.

Answer 1

Use CreateProcess instead of system.

–EDIT–

the code for CreateProcess that I tried is what I found at this url:

The code is a mess, I’d advise to avoid that url in future.

At the end of “CreateProcess” article is a link named “Creating Processes”, which contains simpler example that is easier to read. Use it as a starting point.