v2/ext/env.hpp

0001 // Copyright (c) 2022 Klemens D. Morgenstern
0002 // Copyright (c) 2022 Samuel Venable
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006
0007 #ifndef BOOST_PROCESS_V2_ENV_HPP
0008 #define BOOST_PROCESS_V2_ENV_HPP
0009 #include <string>
0010 #include <vector>
0011
0012 #include <boost/process/v2/detail/config.hpp>
0013 #include <boost/process/v2/detail/throw_error.hpp>
0014 #include <boost/process/v2/process_handle.hpp>
0015 #include <boost/process/v2/pid.hpp>
0016
0017 #include <boost/process/v2/environment.hpp>
0018
0019 BOOST_PROCESS_V2_BEGIN_NAMESPACE
0020
0021 namespace detail
0022 {
0023 namespace ext
0024 {
0025
0026 #if defined(BOOST_PROCESS_V2_WINDOWS)
0027 using native_env_handle_type = wchar_t *;
0028 using native_env_iterator = wchar_t *;
0029 #elif defined(__FreeBSD__)
0030 using native_env_handle_type = char **;
0031 using native_env_iterator = char **;
0032 #else
0033 using native_env_handle_type = char *;
0034 using native_env_iterator = char *;
0035 #endif
0036
0037 struct native_env_handle_deleter
0038 {
0039     BOOST_PROCESS_V2_DECL void operator()(native_env_handle_type) const;
0040 };
0041
0042 BOOST_PROCESS_V2_DECL native_env_iterator next(native_env_iterator nh);
0043 BOOST_PROCESS_V2_DECL native_env_iterator find_end(native_env_iterator nh);
0044 BOOST_PROCESS_V2_DECL const environment::char_type * dereference(native_env_iterator iterator);
0045
0046 } // namespace ext
0047 } // namespace detail
0048
0049 namespace ext {
0050
0051 /// The view of an environment
0052 struct env_view
0053 {
0054     using native_handle_type = detail::ext::native_env_handle_type;
0055     using value_type = environment::key_value_pair_view;
0056
0057     env_view() = default;
0058     env_view(env_view && nt) = default;
0059
0060     native_handle_type native_handle() { return handle_.get(); }
0061
0062
0063     struct iterator
0064     {
0065         using value_type        = environment::key_value_pair_view;
0066         using difference_type   = int;
0067         using reference         = environment::key_value_pair_view;
0068         using pointer           = environment::key_value_pair_view;
0069         using iterator_category = std::forward_iterator_tag;
0070
0071         iterator() = default;
0072         iterator(const iterator & ) = default;
0073         iterator(const detail::ext::native_env_iterator &native_handle) : iterator_(native_handle) {}
0074
0075         iterator & operator++()
0076         {
0077             iterator_ = detail::ext::next(iterator_);
0078             return *this;
0079         }
0080
0081         iterator operator++(int)
0082         {
0083             auto last = *this;
0084             iterator_ = detail::ext::next(iterator_);
0085             return last;
0086         }
0087         environment::key_value_pair_view operator*() const
0088         {
0089             return detail::ext::dereference(iterator_);
0090         }
0091
0092         friend bool operator==(const iterator & l, const iterator & r) {return l.iterator_ == r.iterator_;}
0093         friend bool operator!=(const iterator & l, const iterator & r) {return l.iterator_ != r.iterator_;}
0094
0095       private:
0096         detail::ext::native_env_iterator iterator_;
0097     };
0098
0099     iterator begin() const {return iterator(handle_.get());}
0100     iterator   end() const {return iterator(detail::ext::find_end(handle_.get()));}
0101
0102   private:
0103     friend BOOST_PROCESS_V2_DECL env_view env(pid_type pid, error_code & ec);
0104     #if defined(BOOST_PROCESS_V2_WINDOWS)
0105     friend BOOST_PROCESS_V2_DECL env_view env(HANDLE handle, error_code & ec);
0106     #endif
0107
0108     std::unique_ptr<typename remove_pointer<detail::ext::native_env_handle_type>::type,
0109             detail::ext::native_env_handle_deleter> handle_;
0110 };
0111
0112 #if defined(BOOST_PROCESS_V2_WINDOWS)
0113 BOOST_PROCESS_V2_DECL env_view env(HANDLE handle, error_code & ec);
0114 BOOST_PROCESS_V2_DECL env_view env(HANDLE handle);
0115 #endif
0116
0117 /// @{
0118 /// Get the environment of another process.
0119 BOOST_PROCESS_V2_DECL env_view env(pid_type pid, error_code & ec);
0120 BOOST_PROCESS_V2_DECL env_view env(pid_type pid);
0121
0122 template<typename Executor>
0123 BOOST_PROCESS_V2_DECL env_view env(basic_process_handle<Executor> & handle, error_code & ec)
0124 {
0125 #if defined(BOOST_PROCESS_V2_WINDOWS)
0126     return env(handle.native_handle(), ec);
0127 #else
0128     return env(handle.id(), ec);
0129 #endif
0130 }
0131
0132 template<typename Executor>
0133 BOOST_PROCESS_V2_DECL env_view env(basic_process_handle<Executor> & handle)
0134 {
0135 #if defined(BOOST_PROCESS_V2_WINDOWS)
0136   return env(handle.native_handle());
0137 #else
0138   return env(handle.id());
0139 #endif
0140 }
0141
0142 /// @}
0143
0144
0145
0146 } // namespace ext
0147
0148 BOOST_PROCESS_V2_END_NAMESPACE
0149
0150 #if defined(BOOST_PROCESS_V2_HEADER_ONLY)
0151
0152 #include <boost/process/v2/ext/impl/env.ipp>
0153
0154 #endif
0155 #endif // BOOST_PROCESS_V2_ENV_HPP