VILLASnode/common/include/villas/popen.hpp

/* Bi-directional popen.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include <signal.h>

#include <ext/stdio_filebuf.h>

#include <istream>
#include <map>
#include <memory>
#include <ostream>
#include <string>
#include <vector>

namespace villas {
namespace utils {

class Popen {

public:
  using arg_list = std::vector<std::string>;
  using env_map = std::map<std::string, std::string>;

  using char_type = char;
  using stdio_buf = __gnu_cxx::stdio_filebuf<char_type>;

  Popen(const std::string &cmd, const arg_list &args = arg_list(),
        const env_map &env = env_map(), const std::string &wd = std::string(),
        bool shell = false);
  ~Popen();

  void open();
  int close();
  void kill(int signal = SIGINT);

  int getFdIn() { return fd_in; }

  int getFdOut() { return fd_out; }

  pid_t getPid() const { return pid; }

protected:
  std::string command;
  std::string working_dir;
  arg_list arguments;
  env_map environment;
  bool shell;
  pid_t pid;

  int fd_in, fd_out;
};

class PopenStream : public Popen {

public:
  PopenStream(const std::string &cmd, const arg_list &args = arg_list(),
              const env_map &env = env_map(),
              const std::string &wd = std::string(), bool shell = false);
  ~PopenStream();

  std::istream &cin() { return *(input.stream); }

  std::ostream &cout() { return *(output.stream); }

  void open();
  int close();

protected:
  struct {
    std::unique_ptr<std::istream> stream;
    std::unique_ptr<stdio_buf> buffer;
  } input;

  struct {
    std::unique_ptr<std::ostream> stream;
    std::unique_ptr<stdio_buf> buffer;
  } output;
};

} // namespace utils
} // namespace villas

template <typename T>
std::istream &operator>>(villas::utils::PopenStream &po, T &value) {
  return *(po.input.stream) >> value;
}