How to execute CMD command with CreateProcess - c++

Question

I wanted to execute cmd command like "wmic logicaldisk get name > file.log". I have written the following function but it doesn't work and my program will crash.
bool Information::ExecuteConsoleCommand(QString arg_console_command)
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
ZeroMemory( &pi, sizeof(pi) );
// Start the child process.
if(!CreateProcess(NULL,
(WCHAR*)arg_console_command.toStdWString().c_str(),
NULL, NULL, FALSE,
NORMAL_PRIORITY_CLASS | CREATE_NO_WINDOW,
NULL, NULL, &si, &pi))
{
return false;
}
else
{
return true;
}
// Wait until child process exits.
WaitForSingleObject( pi.hProcess, INFINITE );
// Close process and thread handles.
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
}
How should I fix this function in the order it can execute cmd command? Also, I didn't want to use system() to run my commands because it show console window.

Answer 1

I see tag Qt and parameter's type QString in your question. So, you can use QProcess and QFile, here is example:
#include <QProcess>
#include <QDebug>
#include <QFile>
int main(int /*argc*/, char* /*argv*/[])
{
QProcess process;
process.start("wmic logicaldisk get name");
process.waitForFinished();
auto output = process.readAll();
QFile outputFile("file.log");
outputFile.open(QIODevice::WriteOnly);
outputFile.write(output);
outputFile.close();
return 0;
}
If you want to use CreateProcess, you can do it like this (based on your source):
#include <QString>
#include <Windows.h>
bool ExecuteConsoleCommand(QString arg_console_command)
{
arg_console_command.prepend("/C ");
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
// Start the child process.
if(!CreateProcessW(L"C:\\Windows\\System32\\cmd.exe",
(WCHAR*)arg_console_command.toStdWString().c_str(),
NULL, NULL, FALSE,
NORMAL_PRIORITY_CLASS | CREATE_NO_WINDOW,
NULL, NULL, &si, &pi))
{
return false;
}
// Wait until child process exits.
WaitForSingleObject( pi.hProcess, INFINITE );
// Close process and thread handles.
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
return true;
}
int main(int /*argc*/, char* /*argv*/[])
{
ExecuteConsoleCommand("wmic logicaldisk get name > file.log");
return 0;
}