How to use v2 initializers

[mike-5345]

Hello,

I am excited to use process v2 in my projects. Unfortunately I am having a bit of a hard time understanding the API. If this is not the correct place to post such questions I apologize.

Please see my following example. I cannot get the on_* functions to run. I am sure I am doing something wrong:

namespace asio = boost::asio;
namespace bp = boost::process::v2;
using namespace std::chrono_literals;

struct CustomInit
{
   template <typename Launcher>
   std::error_code on_setup(Launcher&, const std::filesystem::path&, const char * const *&)
   {
      std::cout << "on_setup" << std::endl;
      return {};
   }

   template <typename Launcher>
   std::error_code on_error(Launcher&, const std::filesystem::path&, const char * const *&)
   {
      std::cout << "on_error" << std::endl;
      return {};
   }

   template <typename Launcher>
   std::error_code on_success(Launcher&, const std::filesystem::path&, const char * const *&)
   {
      std::cout << "on_success" << std::endl;
      return {};
   }

   template <typename Launcher>
   std::error_code on_fork_error(Launcher&, const std::filesystem::path&, const char * const *&)
   {
      std::cout << "on_fork_error" << std::endl;
      return {};
   }

   template <typename Launcher>
   std::error_code on_exec_setup(Launcher&, const std::filesystem::path&, const char * const *&)
   {
      std::cout << "on_exec_setup" << std::endl;
      return {};
   }

   template <typename Launcher>
   std::error_code on_exec_error(Launcher&, const std::filesystem::path&, const char * const *&)
   {
      std::cout << "on_exec_error" << std::endl;
      return {};
   }
};

int
main(void)
{
   asio::io_context io;
   
   try {
      auto p = bp::process(io, "/usr/bin/sleep", {"1"}, CustomInit{});

      bp::async_execute(std::move(p),
      [] (const boost::system::error_code &, const int exitCode) {
         std::cout << exitCode << std::endl;
      });

      io.run();
   }
   catch (const std::exception &e) {
      std::cerr << e.what() << std::endl;
   }

   return 0;
}

Thanks in advance for any assistance you can provide.

[mike-5345]

I would like to add that the goal here is to be able to terminate a child process and all of its descendent processes. I was thinking of using the initializers to set a new process group id on start so that I can terminate the whole process as a group from the parent. If there is a better way of doing this please let me know.

Thanks.

[klemens-morgenstern]

You need to return boost::system::error_code and you should check if BOOST_PROCESS_USE_STD_FS is defined.

Otherwise looks correct.