Calling a Python script from C++ 🐍

CMakeLists.txt

cmake_minimum_required(VERSION 3.12)
project(popen)

set(CMAKE_CXX_STANDARD 11)

add_executable(popen main.cpp)

install(FILES hello.py
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})

hello.py

#!/usr/bin/env python3

import sys

if __name__ == '__main__':
    print("Hello World!")
    print(sys.argv)

main.cpp

#include <iostream>
#include <array>

std::string call(const std::string& command) {
    std::array<char, 128> buffer{};
    std::string result;

    FILE *pipe = popen(command.c_str(), "r");
    if (!pipe) {
        std::cerr << "Couldn't start command." << std::endl;
        return nullptr;
    }
    while (fgets(buffer.data(), 128, pipe) != nullptr) {
        result += buffer.data();
    }
    int code = pclose(pipe);

    return result;
}

int main() {
    std::cout << call("/usr/bin/python hello.py world") << std::endl;

    return 0;
}