CreateProcess执行EXE

Question

I have an application where the user uploads a file to the remote server, the same server to receive this file should run this application. I'm using the CreateProcess method. The problem is, the file directory is already defined in a std :: string, and I'm having difficulties to pass this directory as a parameter to the CreateProcess.

How do I that this directory can be passed to the CreateProcess without errors?

    //the client remotely sends the directory where the file will be saved
    socket_setup.SEND_BUFFER("\nRemote directory for upload: ");
    char *dirUP_REMOTE = socket_setup.READ_BUFFER();
    std::string DIRETORIO_UP = dirUP_REMOTE; // variable where it stores the remote directory


        //after uploading this is validation for executing file
if (!strcmp(STRCMP_EXECUTE, EXECUTE_TIME_YES))
{
    STARTUPINFO si;
    PROCESS_INFORMATION pi;
    ZeroMemory( &si, sizeof(si) );
    si.cb = sizeof(si);
    ZeroMemory( &pi, sizeof(pi) );

    std::wstring wdirectory;
    int slength = (int)directory.length() + 1;
    int len = MultiByteToWideChar(CP_ACP, 0, directory.c_str(), slength, 0, 0);
    wdirectory.resize(len);
    MultiByteToWideChar(CP_ACP, 0, directory.c_str(), slength, &wdirectory[0], len);
    if (!CreateProcess(NULL, wdirectory.c_str(), NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi));
}

Answer 1

There are two versions of CreateProcess: CreateProcessA and CreateProcessW (like most similar windows APIs). The right version is used depending on whether you have Unicode enabled. Here you need to convert your std::string to a std::wstring first, because that CreateProcess is actually a CreateProcessW.

std::wstring wdirectory;
int slength = (int)directory.length() + 1;
int len = MultiByteToWideChar(CP_ACP, 0, directory.c_str(), slength, 0, 0); 
wdirectory.resize(len);
MultiByteToWideChar(CP_ACP, 0, directory.c_str(), slength, &wdirectory[0], len);
//...
if (!CreateProcess(NULL,(LPWSTR)wdirectory.c_str(), NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi));

You could also try replacing CreateProcess by a manual call to CreateProcessA and passing the cstring like you tried to do in the question, but then you won't support wide characters :

if (!CreateProcessA(NULL, directory.c_str(), NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi));