env_utils.hpp

//--------------------------------------------------------------------------------------------------
// Copyright (c) 2020 Marcus Geelnard
//
// This software is provided 'as-is', without any express or implied warranty. In no event will the
// authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose, including commercial
// applications, and to alter it and redistribute it freely, subject to the following restrictions:
//
//  1. The origin of this software must not be misrepresented; you must not claim that you wrote
//     the original software. If you use this software in a product, an acknowledgment in the
//     product documentation would be appreciated but is not required.
//
//  2. Altered source versions must be plainly marked as such, and must not be misrepresented as
//     being the original software.
//
//  3. This notice may not be removed or altered from any source distribution.
//--------------------------------------------------------------------------------------------------
 
#ifndef BUILDCACHE_ENV_UTILS_HPP_
#define BUILDCACHE_ENV_UTILS_HPP_
 
#include <string>
 
namespace bcache {
class env_var_t {
public:
  env_var_t(const std::string& name);
 
  operator bool() const {
    return m_defined;
  }
 
  const std::string& as_string() const {
    return m_value;
  }
 
  int64_t as_int64() const;
 
  bool as_bool() const;
 
private:
  std::string m_value;
  bool m_defined;
};
 
class scoped_set_env_t {
public:
  scoped_set_env_t(const std::string& name, const std::string& value);
 
  ~scoped_set_env_t();
 
private:
  std::string m_name;
  env_var_t m_old_env_var;
};
 
class scoped_unset_env_t {
public:
  scoped_unset_env_t(const std::string& name);
 
  ~scoped_unset_env_t();
 
private:
  std::string m_name;
  env_var_t m_old_env_var;
};
 
bool env_defined(const std::string& env_var);
 
std::string get_env(const std::string& env_var);
 
void set_env(const std::string& env_var, const std::string& value);
 
void unset_env(const std::string& env_var);
 
}  // namespace bcache
 
#endif  // BUILDCACHE_ENV_UTILS_HPP_