ian@0: //
ian@0: // Boost.Process
ian@0: // ~~~~~~~~~~~~~
ian@0: //
ian@0: // Copyright (c) 2006, 2007 Julio M. Merino Vidal
ian@0: // Copyright (c) 2008 Ilya Sokolov, Boris Schaeling
ian@0: // Copyright (c) 2009 Boris Schaeling
ian@0: // Copyright (c) 2010 Felipe Tanus, Boris Schaeling
ian@0: //
ian@0: // Distributed under the Boost Software License, Version 1.0. (See accompanying
ian@0: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
ian@0: //
ian@0: 
ian@0: /**
ian@0:  * \file boost/process/detail/posix_helpers.hpp
ian@0:  *
ian@0:  * Includes the declaration of helper functions for POSIX systems.
ian@0:  */
ian@0: 
ian@0: #ifndef BOOST_PROCESS_POSIX_HELPERS_HPP
ian@0: #define BOOST_PROCESS_POSIX_HELPERS_HPP
ian@0: 
ian@0: #include <boost/process/config.hpp>
ian@0: #include <boost/process/environment.hpp>
ian@0: #include <string>
ian@0: #include <utility>
ian@0: #include <cstring>
ian@0: #include <cstddef>
ian@0: 
ian@0: namespace boost {
ian@0: namespace process {
ian@0: namespace detail {
ian@0: 
ian@0: /**
ian@0:  * Converts an environment to a char** table as used by execve().
ian@0:  *
ian@0:  * Converts the environment's contents to the format used by the
ian@0:  * execve() system call. The returned char** array is allocated
ian@0:  * in dynamic memory; the caller must free it when not used any
ian@0:  * more. Each entry is also allocated in dynamic memory and is a
ian@0:  * NULL-terminated string of the form var=value; these must also be
ian@0:  * released by the caller.
ian@0:  *
ian@0:  * This operation is only available on POSIX systems.
ian@0:  *
ian@0:  * \return The first argument of the pair is an integer that indicates
ian@0:  *         how many strings are stored in the second argument. The
ian@0:  *         second argument is a NULL-terminated, dynamically allocated
ian@0:  *         array of dynamically allocated strings representing the
ian@0:  *         enviroment's content. Each array entry is a NULL-terminated
ian@0:  *         string of the form var=value. The caller is responsible for
ian@0:  *         freeing them.
ian@0:  */
ian@0: inline std::pair<std::size_t, char**> environment_to_envp(const environment
ian@0:     &env)
ian@0: {
ian@0:     std::size_t nargs = env.size();
ian@0:     char **envp = new char*[nargs + 1];
ian@0:     environment::size_type i = 0;
ian@0:     for (environment::const_iterator it = env.begin(); it != env.end(); ++it)
ian@0:     {
ian@0:         std::string s = it->first + "=" + it->second;
ian@0:         envp[i] = new char[s.size() + 1];
ian@0:         std::strncpy(envp[i], s.c_str(), s.size() + 1);
ian@0:         ++i;
ian@0:     }
ian@0:     envp[i] = 0;
ian@0:     return std::pair<std::size_t, char**>(nargs, envp);
ian@0: }
ian@0: 
ian@0: /**
ian@0:  * Converts the command line to an array of C strings.
ian@0:  *
ian@0:  * Converts the command line's list of arguments to the format expected
ian@0:  * by the \a argv parameter in the POSIX execve() system call.
ian@0:  *
ian@0:  * This operation is only available on POSIX systems.
ian@0:  *
ian@0:  * \return The first argument of the pair is an integer that indicates
ian@0:  *         how many strings are stored in the second argument. The
ian@0:  *         second argument is a NULL-terminated, dynamically allocated
ian@0:  *         array of dynamically allocated strings holding the arguments
ian@0:  *         to the executable. The caller is responsible for freeing them.
ian@0:  */
ian@0: template <class Arguments>
ian@0: inline std::pair<std::size_t, char**> collection_to_argv(const Arguments &args)
ian@0: {
ian@0:     std::size_t nargs = args.size();
ian@0:     char **argv = new char*[nargs + 1];
ian@0:     typename Arguments::size_type i = 0;
ian@0:     for (typename Arguments::const_iterator it = args.begin(); it != args.end();
ian@0:         ++it)
ian@0:     {
ian@0:         argv[i] = new char[it->size() + 1];
ian@0:         std::strncpy(argv[i], it->c_str(), it->size() + 1);
ian@0:         ++i;
ian@0:     }
ian@0:     argv[nargs] = 0;
ian@0:     return std::pair<std::size_t, char**>(nargs, argv);
ian@0: }
ian@0: 
ian@0: }
ian@0: }
ian@0: }
ian@0: 
ian@0: #endif