redirection.hpp

#ifndef __COMMON_REDIRECTION_HPP__
#define __COMMON_REDIRECTION_HPP__
#include <memory>
#include <optional>
#include <sstream>
#include <string>
namespace IO
{
  enum RedirectionType
  {
    Buffer,
    File
  };
 
  class RedirectGuard;
 
  class RedirectHandle
  {
  public:
    RedirectHandle(std::shared_ptr<RedirectGuard> owner,
                   std::shared_ptr<bool> active_flag,
                   bool owns,
                   RedirectionType _type);
 
    ~RedirectHandle();
 
    RedirectHandle(const RedirectHandle&) = delete;
    RedirectHandle& operator=(const RedirectHandle&) = delete;
 
    RedirectHandle(RedirectHandle&&) = default;
    RedirectHandle& operator=(RedirectHandle&&) = default;
 
  private:
    std::shared_ptr<RedirectGuard> owner_ptr;
    std::shared_ptr<bool> active_flag;
    bool owns_guard = false;
    [[maybe_unused]] RedirectionType type;
  };
 
  class RedirectGuard : public std::enable_shared_from_this<RedirectGuard>
  {
  public:
    RedirectGuard();
 
    [[nodiscard("Handle must be held")]] RedirectHandle redirect();
 
    [[nodiscard("Handle must be held")]] RedirectHandle redirect_to_file();
 
    void restore();
 
    std::optional<std::string> getCapturedOutput() const;
 
  private:
    friend class RedirectHandle;
 
    bool has_been_redirected = false;
    std::streambuf* coutbuf = nullptr;
    std::stringstream buffer;
    int original_stdout_fd = -1;
 
    std::shared_ptr<bool> active_flag;
  };
} // namespace IO
#endif