Using a string in system() (maybe system_() )

Question

my problem would be using a string in system(). As you might know you can use console commands in c++ with system() (or system_() if you realy want to :|) I want to make a simple Texteditor where the user can paste a filepath and then edit the file directly in the console. (for learning purposes) i simply get the string throught std::cin and then throw it in system() for the directory change throught "cd". Well thats not working because for no reason system() needs a const char pointer as the argument. after converting the string throught ".data()" and pasting the pointer in the system() funktion it wont change the directory AND doesn´t throw a error or crashes

`

#pragma once

#include <Windows.h>
#include <fstream>
#include <iostream>
#include <ostream>
#include <istream>
#include <string>

using std::fstream;

using namespace std;

int start_doin_da_stream(string h, string filename) {

    //now the parsing of the content into the cmd-shell shall beginn

    system("color 1b");
    string file = h;

    //changing directory
    string doc = file + '/' + filename;
    doc = "cd " + file;


    //maybe the issue
    char const* foo = doc.data();
    //

    system(foo);
    system("dir");

    //creating a file stream
    fstream stream(filename, std::ios::out | std::ios::app);

    //checking for living stream
    bool alive = true;
    if (alive != stream.good()) {
        std::cout << "my men... your file deaddd!!!";
        return 0;
    }
    else
    {
        std::cout << "Its alive yeahhhhhh!!!!!";
        std::this_thread::sleep_for(std::chrono::milliseconds(100000));
    }

    //if alive true gehts weiter ans schreiben in die Konsole

    return 0;
}

`

i don´t really know what else i could try because i am relatively new to programming so i appreciate the help :)

Well i fucked up with the string. thx guys.

A more serious problem is that the whole purpose of my code is nonesense that i understood after reading G.M. ´s comment about mother and child processes. My understanding of c++ console applications was seriously lacking as i didnt knew that the console and the programm are 2 different threads. Thanks G.M. for your knowledge. I´ll try to get a workaround. There might be a solution to my problem already.

xD it was one damn function. the name is... hold yourself... SetCurrentDirectory() :|

Answer 1

you might have to transform your std::string into a c_string via the function c_str() (pay attention to single/double quotes).

string doc = file + "/" + filename;
doc = "cd " + file;

system(doc.c_str());

also checking the return value of system might help you. It should return a 0 value if everything is correct. So you can just do this

string doc = file + "/" + filename;
doc = "cd " + file;

if(system(doc.c_str()))
    std::cout << "ERROR\n";

[UPDATE]

since the provided code is a bit weird this could be a more concrete solution

int start_doin_da_stream(string path, string filename) {

//now the parsing of the content into the cmd-shell shall beginn
system("color 1b");

//changing directory
string file_path = "cd " + path;
system(file_path.c_str());

//creating a file stream
fstream stream(filename, std::ios::out | std::ios::app);

//checking for living stream
bool alive = true;
if (alive != stream.good()) {
    std::cout << "my men... your file deaddd!!!";
    return 1; // you might want something different from 0 in order to debug the error
}
else // this else is not wrong but avoidable since the true condition has a return statement
{
    std::cout << "Its alive yeahhhhhh!!!!!";
    std::this_thread::sleep_for(std::chrono::milliseconds(100000));
}

//if alive true ghets weiter ans schreiben in die Konsole

return 0;

}