552 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			552 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C++
		
	
	
		
			Executable File
		
	
	
	
	
| // Copyright (c) 2016 Klemens D. Morgenstern
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| //
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| // Distributed under the Boost Software License, Version 1.0. (See accompanying
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| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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| 
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| #ifndef BOOST_PROCESS_IO_HPP_
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| #define BOOST_PROCESS_IO_HPP_
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| 
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| #include <iosfwd>
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| #include <cstdio>
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| #include <functional>
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| #include <utility>
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| #include <boost/process/detail/config.hpp>
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| #include <boost/process/pipe.hpp>
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| 
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| #include <future>
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| 
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| #if defined(BOOST_POSIX_API)
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| #include <boost/process/detail/posix/asio_fwd.hpp>
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| #include <boost/process/detail/posix/close_in.hpp>
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| #include <boost/process/detail/posix/close_out.hpp>
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| #include <boost/process/detail/posix/null_in.hpp>
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| #include <boost/process/detail/posix/null_out.hpp>
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| #include <boost/process/detail/posix/file_in.hpp>
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| #include <boost/process/detail/posix/file_out.hpp>
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| #include <boost/process/detail/posix/pipe_in.hpp>
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| #include <boost/process/detail/posix/pipe_out.hpp>
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| #elif defined(BOOST_WINDOWS_API)
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| #include <boost/process/detail/windows/asio_fwd.hpp>
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| #include <boost/process/detail/windows/close_in.hpp>
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| #include <boost/process/detail/windows/close_out.hpp>
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| #include <boost/process/detail/windows/null_in.hpp>
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| #include <boost/process/detail/windows/null_out.hpp>
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| #include <boost/process/detail/windows/file_in.hpp>
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| #include <boost/process/detail/windows/file_out.hpp>
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| #include <boost/process/detail/windows/pipe_in.hpp>
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| #include <boost/process/detail/windows/pipe_out.hpp>
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| #endif
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| 
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| /** \file boost/process/io.hpp
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|  *
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|  *    Header which provides the io properties. It provides the following properties:
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|  *
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| \xmlonly
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| <programlisting>
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| namespace boost {
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|   namespace process {
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|     <emphasis>unspecified</emphasis> <globalname alt="boost::process::close">close</globalname>;
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|     <emphasis>unspecified</emphasis> <globalname alt="boost::process::null">null</globalname>;
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|     <emphasis>unspecified</emphasis> <globalname alt="boost::process::std_in">std_in</globalname>;
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|     <emphasis>unspecified</emphasis> <globalname alt="boost::process::std_out">std_out</globalname>;
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|     <emphasis>unspecified</emphasis> <globalname alt="boost::process::std_err">std_err</globalname>;
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|   }
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| }
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| </programlisting>
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| \endxmlonly
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| 
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| \par File I/O
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| 
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| The library allows full redirection of streams to files as shown below.
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| 
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| \code{.cpp}
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| boost::filesystem::path log    = "my_log_file.txt";
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| boost::filesystem::path input  = "input.txt";
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| boost::filesystem::path output = "output.txt";
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| system("my_prog", std_out>output, std_in<input, std_err>log);
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| \endcode
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| 
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| \par Synchronous Pipe I/O
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| 
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| Another way is to communicate through pipes.
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| 
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| \code{.cpp}
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| pstream str;
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| child c("my_prog", std_out > str);
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| 
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| int i;
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| str >> i;
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| \endcode
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| 
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| Note that the pipe may also be used between several processes, like this:
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| 
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| \code{.cpp}
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| pipe p;
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| child c1("nm", "a.out", std_out>p);
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| child c2("c++filt", std_in<p);
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| \endcode
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| 
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| \par Asynchronous I/O
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| 
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| Utilizing `boost.asio` asynchronous I/O is provided.
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| 
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| \code
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| boost::asio::io_context ios;
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| std::future<std::string> output;
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| system("ls", std_out > output, ios);
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| 
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| auto res = fut.get();
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| \endcode
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| 
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| \note `boost/process/async.hpp` must also be included for this to work.
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| 
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| \par Closing
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| 
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| Stream can be closed, so nothing can be read or written.
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| 
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| \code{.cpp}
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| system("foo", std_in.close());
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| \endcode
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| 
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| \par Null
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| 
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| Streams can be redirected to null, which means, that written date will be
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| discarded and read data will only contain `EOF`.
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| 
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| \code{.cpp}
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| system("b2", std_out > null);
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| \endcode
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| 
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|  *
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|  */
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| 
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| namespace boost { namespace process { namespace detail {
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| 
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| 
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| template<typename T> using is_streambuf    = typename std::is_same<T, boost::asio::streambuf>::type;
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| template<typename T> using is_const_buffer =
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|         std::integral_constant<bool,
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|             std::is_same<   boost::asio::const_buffer, T>::value |
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|             std::is_base_of<boost::asio::const_buffer, T>::value
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|         >;
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| template<typename T> using is_mutable_buffer =
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|         std::integral_constant<bool,
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|             std::is_same<   boost::asio::mutable_buffer, T>::value |
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|             std::is_base_of<boost::asio::mutable_buffer, T>::value
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|         >;
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| 
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| 
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| struct null_t  {constexpr null_t() = default;};
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| struct close_t;
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| 
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| template<class>
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| struct std_in_
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| {
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|     constexpr std_in_() = default;
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| 
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|     api::close_in close() const {return api::close_in(); }
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|     api::close_in operator=(const close_t &) const {return api::close_in();}
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|     api::close_in operator<(const close_t &) const {return api::close_in();}
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| 
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|     api::null_in null() const {return api::null_in();}
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|     api::null_in operator=(const null_t &) const {return api::null_in();}
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|     api::null_in operator<(const null_t &) const {return api::null_in();}
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| 
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|     api::file_in operator=(const boost::filesystem::path &p) const {return p;}
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|     api::file_in operator=(const std::string & p)            const {return p;}
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|     api::file_in operator=(const std::wstring &p)            const {return p;}
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|     api::file_in operator=(const char * p)                   const {return p;}
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|     api::file_in operator=(const wchar_t * p)                const {return p;}
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| 
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|     api::file_in operator<(const boost::filesystem::path &p) const {return p;}
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|     api::file_in operator<(const std::string &p)             const {return p;}
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|     api::file_in operator<(const std::wstring &p)            const {return p;}
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|     api::file_in operator<(const char*p)                     const {return p;}
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|     api::file_in operator<(const wchar_t * p)                const {return p;}
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| 
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|     api::file_in operator=(FILE * f)                         const {return f;}
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|     api::file_in operator<(FILE * f)                         const {return f;}
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| 
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|     template<typename Char, typename Traits> api::pipe_in operator=(basic_pipe<Char, Traits> & p)      const {return p;}
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|     template<typename Char, typename Traits> api::pipe_in operator<(basic_pipe<Char, Traits> & p)      const {return p;}
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|     template<typename Char, typename Traits> api::pipe_in operator=(basic_opstream<Char, Traits> & p)  const {return p.pipe();}
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|     template<typename Char, typename Traits> api::pipe_in operator<(basic_opstream<Char, Traits> & p)  const {return p.pipe();}
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|     template<typename Char, typename Traits> api::pipe_in operator=(basic_pstream <Char, Traits> & p)  const {return p.pipe();}
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|     template<typename Char, typename Traits> api::pipe_in operator<(basic_pstream <Char, Traits> & p)  const {return p.pipe();}
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| 
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|     api::async_pipe_in operator=(async_pipe & p) const {return p;}
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|     api::async_pipe_in operator<(async_pipe & p) const {return p;}
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| 
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|     template<typename T, typename = typename std::enable_if<
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|             is_const_buffer<T>::value || is_mutable_buffer<T>::value
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|             >::type>
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|     api::async_in_buffer<const T> operator=(const T & buf) const {return buf;}
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|     template<typename T, typename = typename std::enable_if<is_streambuf<T>::value>::type >
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|     api::async_in_buffer<T>       operator=(T       & buf) const {return buf;}
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| 
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|     template<typename T, typename = typename std::enable_if<
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|             is_const_buffer<T>::value || is_mutable_buffer<T>::value
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|             >::type>
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|     api::async_in_buffer<const T> operator<(const T & buf) const {return buf;}
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|     template<typename T, typename = typename std::enable_if<is_streambuf<T>::value>::type >
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|     api::async_in_buffer<T>       operator<(T       & buf) const {return buf;}
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| 
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| };
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| 
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| //-1 == empty.
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| //1 == stdout
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| //2 == stderr
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| template<int p1, int p2 = -1>
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| struct std_out_
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| {
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|     constexpr std_out_() = default;
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| 
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|     api::close_out<p1,p2> close() const {return api::close_out<p1,p2>(); }
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|     api::close_out<p1,p2> operator=(const close_t &) const {return api::close_out<p1,p2>();}
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|     api::close_out<p1,p2> operator>(const close_t &) const {return api::close_out<p1,p2>();}
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| 
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|     api::null_out<p1,p2> null() const {return api::null_out<p1,p2>();}
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|     api::null_out<p1,p2> operator=(const null_t &) const {return api::null_out<p1,p2>();}
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|     api::null_out<p1,p2> operator>(const null_t &) const {return api::null_out<p1,p2>();}
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| 
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|     api::file_out<p1,p2> operator=(const boost::filesystem::path &p) const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator=(const std::string &p)             const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator=(const std::wstring &p)            const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator=(const char * p)                   const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator=(const wchar_t * p)                const {return api::file_out<p1,p2>(p);}
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| 
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|     api::file_out<p1,p2> operator>(const boost::filesystem::path &p) const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator>(const std::string &p)             const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator>(const std::wstring &p)            const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator>(const char * p)                   const {return api::file_out<p1,p2>(p);}
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|     api::file_out<p1,p2> operator>(const wchar_t * p)                const {return api::file_out<p1,p2>(p);}
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| 
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|     api::file_out<p1,p2> operator=(FILE * f)  const {return f;}
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|     api::file_out<p1,p2> operator>(FILE * f)  const {return f;}
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| 
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|     template<typename Char, typename Traits> api::pipe_out<p1,p2> operator=(basic_pipe<Char, Traits> & p)      const {return p;}
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|     template<typename Char, typename Traits> api::pipe_out<p1,p2> operator>(basic_pipe<Char, Traits> & p)      const {return p;}
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|     template<typename Char, typename Traits> api::pipe_out<p1,p2> operator=(basic_ipstream<Char, Traits> & p)  const {return p.pipe();}
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|     template<typename Char, typename Traits> api::pipe_out<p1,p2> operator>(basic_ipstream<Char, Traits> & p)  const {return p.pipe();}
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|     template<typename Char, typename Traits> api::pipe_out<p1,p2> operator=(basic_pstream <Char, Traits> & p)  const {return p.pipe();}
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|     template<typename Char, typename Traits> api::pipe_out<p1,p2> operator>(basic_pstream <Char, Traits> & p)  const {return p.pipe();}
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| 
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|     api::async_pipe_out<p1, p2> operator=(async_pipe & p) const {return p;}
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|     api::async_pipe_out<p1, p2> operator>(async_pipe & p) const {return p;}
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| 
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|     api::async_out_buffer<p1, p2, const asio::mutable_buffer>     operator=(const asio::mutable_buffer & buf)     const {return buf;}
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|     api::async_out_buffer<p1, p2, const asio::mutable_buffers_1> operator=(const asio::mutable_buffers_1 & buf) const {return buf;}
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|     api::async_out_buffer<p1, p2, asio::streambuf>               operator=(asio::streambuf & os)                   const {return os ;}
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| 
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|     api::async_out_buffer<p1, p2, const asio::mutable_buffer>     operator>(const asio::mutable_buffer & buf)     const {return buf;}
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|     api::async_out_buffer<p1, p2, const asio::mutable_buffers_1> operator>(const asio::mutable_buffers_1 & buf) const {return buf;}
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|     api::async_out_buffer<p1, p2, asio::streambuf>               operator>(asio::streambuf & os)                   const {return os ;}
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| 
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|     api::async_out_future<p1,p2, std::string>       operator=(std::future<std::string> & fut)       const { return fut;}
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|     api::async_out_future<p1,p2, std::string>       operator>(std::future<std::string> & fut)       const { return fut;}
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|     api::async_out_future<p1,p2, std::vector<char>> operator=(std::future<std::vector<char>> & fut) const { return fut;}
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|     api::async_out_future<p1,p2, std::vector<char>> operator>(std::future<std::vector<char>> & fut) const { return fut;}
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| 
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|     template<int pin, typename = typename std::enable_if<
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|             (((p1 == 1) && (pin == 2)) ||
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|              ((p1 == 2) && (pin == 1)))
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|              && (p2 == -1)>::type>
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|     constexpr std_out_<1, 2> operator& (const std_out_<pin>&) const
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|     {
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|         return std_out_<1, 2> ();
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|     }
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| 
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| };
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| 
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| struct close_t
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| {
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|     constexpr close_t() = default;
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|     template<int T, int U>
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|     api::close_out<T,U> operator()(std_out_<T,U>) {return api::close_out<T,U>();}
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| };
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| 
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| 
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| 
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| }
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| ///This constant is a utility to allow syntax like `std_out > close` for closing I/O streams.
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| constexpr boost::process::detail::close_t close;
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| ///This constant is a utility to redirect streams to the null-device.
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| constexpr boost::process::detail::null_t  null;
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| 
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| /**
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| This property allows to set the input stream for the child process.
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| 
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| \section stdin_details Details
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| 
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| \subsection stdin_file File Input
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| 
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| The file I/O simple redirects the stream to a file, for which the possible types are
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| 
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|  - `boost::filesystem::path`
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|  - `std::basic_string<char_type>`
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|  - `const char_type*`
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|  - `FILE*`
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| 
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| with `char_type` being either `char` or `wchar_t`.
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| 
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| FILE* is explicitly added, so the process can easily redirect the output stream
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| of the child to another output stream of the process. That is:
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| 
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| \code{.cpp}
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| system("ls", std_in < stdin);
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| \endcode
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| 
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| \warning If the launching and the child process use the input, this leads to undefined behaviour.
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| 
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| A syntax like `system("ls", std_out > std::cerr)` is not possible, due to the C++
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| implementation not providing access to the handle.
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| 
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| The valid expressions for this property are
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| 
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| \code{.cpp}
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| std_in < file;
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| std_in = file;
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| \endcode
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| 
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| \subsection stdin_pipe Pipe Input
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| 
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| As explained in the corresponding section, the boost.process library provides a
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| @ref boost::process::async_pipe "async_pipe" class which can be
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| used to communicate with child processes.
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| 
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| \note Technically the @ref boost::process::async_pipe "async_pipe"
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| works synchronous here, since no asio implementation is used by the library here.
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| The async-operation will then however not end if the process is finished, since
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| the pipe remains open. You can use the async_close function with on_exit to fix that.
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| 
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| Valid expressions with pipes are these:
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| 
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| \code{.cpp}
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| std_in < pipe;
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| std_in = pipe;
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| \endcode
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| 
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| Where the valid types for `pipe` are the following:
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| 
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|  - `basic_pipe`
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|  - `async_pipe`
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|  - `basic_opstream`
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|  - `basic_pstream`
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| 
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| Note that the pipe may also be used between several processes, like this:
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| 
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| \code{.cpp}
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| pipe p;
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| child c1("nm", "a.out", std_out>p);
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| child c2("c++filt", std_in<p);
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| \endcode
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| 
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| \subsection stdin_async_pipe Asynchronous Pipe Input
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| 
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| Asynchronous Pipe I/O classifies communication which has automatically handling
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| of the asynchronous operations by the process library. This means, that a pipe will be
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| constructed, the async_read/-write will be automatically started, and that the
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| end of the child process will also close the pipe.
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| 
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| Valid types for pipe I/O are the following:
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| 
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|  - `boost::asio::const_buffer`   \xmlonly <footnote><para> Constructed with <code>boost::asio::buffer</code></para></footnote> \endxmlonly
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|  - `boost::asio::mutable_buffer` \xmlonly <footnote><para> Constructed with <code>boost::asio::buffer</code></para></footnote> \endxmlonly
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|  - `boost::asio::streambuf`
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| 
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| Valid expressions with pipes are these:
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| 
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| \code{.cpp}
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| std_in < buffer;
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| std_in = buffer;
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| std_out > buffer;
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| std_out = buffer;
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| std_err > buffer;
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| std_err = buffer;
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| (std_out & std_err) > buffer;
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| (std_out & std_err) = buffer;
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| \endcode
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| 
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| \note  It is also possible to get a future for std_in, by chaining another `std::future<void>` onto it,
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| so you can wait for the input to be completed. It looks like this:
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| \code{.cpp}
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| std::future<void> fut;
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| boost::asio::io_context ios;
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| std::string data;
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| child c("prog", std_in < buffer(data) >  fut, ios);
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| fut.get();
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| \endcode
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| 
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| 
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| \note `boost::asio::buffer` is also available in the `boost::process` namespace.
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| 
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| \warning This feature requires `boost/process/async.hpp` to be included and a reference to `boost::asio::io_context` to be passed to the launching function.
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| 
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| 
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| \subsection stdin_close Close
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| 
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| The input stream can be closed, so it cannot be read from. This will lead to an error when attempted.
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| 
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| This can be achieved by the following syntax.
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| 
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| \code{.cpp}
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| std_in < close;
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| std_in = close;
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| std_in.close();
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| \endcode
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| 
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| \subsection stdin_null Null
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| 
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| The input stream can be redirected to read from the null-device, which means that only `EOF` is read.
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| 
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| The syntax to achieve that has the following variants:
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| 
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| \code{.cpp}
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| std_in < null;
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| std_in = null;
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| std_in.null();
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| \endcode
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| 
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| */
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| 
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| constexpr boost::process::detail::std_in_<void>   std_in;
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| 
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| /**
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| This property allows to set the output stream for the child process.
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| 
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| \note The Semantic is the same as for \xmlonly <globalname alt="boost::process::std_err">std_err</globalname> \endxmlonly
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| 
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| \note `std_err` and `std_out` can be combined into one stream, with the `operator &`, i.e. `std_out & std_err`.
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| 
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| \section stdout_details Details
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| 
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| \subsection stdout_file File Input
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| 
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| The file I/O simple redirects the stream to a file, for which the possible types are
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| 
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|  - `boost::filesystem::path`
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|  - `std::basic_string<char_type>`
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|  - `const char_type*`
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|  - `FILE*`
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| 
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| with `char_type` being either `char` or `wchar_t`.
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| 
 | |
| FILE* is explicitly added, so the process can easily redirect the output stream
 | |
| of the child to another output stream of the process. That is:
 | |
| 
 | |
| \code{.cpp}
 | |
| system("ls", std_out < stdin);
 | |
| \endcode
 | |
| 
 | |
| \warning If the launching and the child process use the input, this leads to undefined behaviour.
 | |
| 
 | |
| A syntax like `system("ls", std_out > std::cerr)` is not possible, due to the C++
 | |
| implementation not providing access to the handle.
 | |
| 
 | |
| The valid expressions for this property are
 | |
| 
 | |
| \code{.cpp}
 | |
| std_out < file;
 | |
| std_out = file;
 | |
| \endcode
 | |
| 
 | |
| \subsection stdout_pipe Pipe Output
 | |
| 
 | |
| As explained in the corresponding section, the boost.process library provides a
 | |
| @ref boost::process::async_pipe "async_pipe" class which can be
 | |
| used to communicate with child processes.
 | |
| 
 | |
| \note Technically the @ref boost::process::async_pipe "async_pipe"
 | |
| works like a synchronous pipe here, since no asio implementation is used by the library here.
 | |
| The asynchronous operation will then however not end if the process is finished, since
 | |
| the pipe remains open. You can use the async_close function with on_exit to fix that.
 | |
| 
 | |
| Valid expressions with pipes are these:
 | |
| 
 | |
| \code{.cpp}
 | |
| std_out > pipe;
 | |
| std_out = pipe;
 | |
| \endcode
 | |
| 
 | |
| Where the valid types for `pipe` are the following:
 | |
| 
 | |
|  - `basic_pipe`
 | |
|  - `async_pipe`
 | |
|  - `basic_ipstream`
 | |
|  - `basic_pstream`
 | |
| 
 | |
| Note that the pipe may also be used between several processes, like this:
 | |
| 
 | |
| \code{.cpp}
 | |
| pipe p;
 | |
| child c1("nm", "a.out", std_out>p);
 | |
| child c2("c++filt", std_in<p);
 | |
| \endcode
 | |
| 
 | |
| \subsection stdout_async_pipe Asynchronous Pipe Output
 | |
| 
 | |
| Asynchronous Pipe I/O classifies communication which has automatically handling
 | |
| of the async operations by the process library. This means, that a pipe will be
 | |
| constructed, the async_read/-write will be automatically started, and that the
 | |
| end of the child process will also close the pipe.
 | |
| 
 | |
| Valid types for pipe I/O are the following:
 | |
| 
 | |
|  - `boost::asio::mutable_buffer` \xmlonly <footnote><para> Constructed with <code>boost::asio::buffer</code></para></footnote> \endxmlonly
 | |
|  - `boost::asio::streambuf`
 | |
|  - `std::future<std::vector<char>>`
 | |
|  - `std::future<std::string>`
 | |
| 
 | |
| Valid expressions with pipes are these:
 | |
| 
 | |
| \code{.cpp}
 | |
| std_out > buffer;
 | |
| std_out = buffer;
 | |
| std_err > buffer;
 | |
| std_err = buffer;
 | |
| (std_out & std_err) > buffer;
 | |
| (std_out & std_err) = buffer;
 | |
| \endcode
 | |
| 
 | |
| \note `boost::asio::buffer` is also available in the `boost::process` namespace.
 | |
| 
 | |
| \warning This feature requires `boost/process/async.hpp` to be included and a reference to `boost::asio::io_context` to be passed to the launching function.
 | |
| 
 | |
| 
 | |
| \subsection stdout_close Close
 | |
| 
 | |
| The out stream can be closed, so it cannot be write from.
 | |
| This will lead to an error when attempted.
 | |
| 
 | |
| This can be achieved by the following syntax.
 | |
| 
 | |
| \code{.cpp}
 | |
| std_out > close;
 | |
| std_out = close;
 | |
| std_out.close();
 | |
| \endcode
 | |
| 
 | |
| \subsection stdout_null Null
 | |
| 
 | |
| The output stream can be redirected to write to the null-device,
 | |
| which means that all output is discarded.
 | |
| 
 | |
| The syntax to achieve that has the following variants:
 | |
| 
 | |
| \code{.cpp}
 | |
| std_out > null;
 | |
| std_out = null;
 | |
| std_out.null();
 | |
| \endcode
 | |
| 
 | |
| */
 | |
| 
 | |
| constexpr boost::process::detail::std_out_<1> std_out;
 | |
| /**This property allows setting the `stderr` stream. The semantic and syntax is the same as for
 | |
|  * \xmlonly <globalname alt="boost::process::std_out">std_out</globalname> \endxmlonly .
 | |
|  */
 | |
| constexpr boost::process::detail::std_out_<2> std_err;
 | |
| 
 | |
| }}
 | |
| #endif /* INCLUDE_BOOST_PROCESS_IO_HPP_ */
 |