boost/process/shell.hpp

0001 // Copyright (c) 2006, 2007 Julio M. Merino Vidal
0002 // Copyright (c) 2008 Ilya Sokolov, Boris Schaeling
0003 // Copyright (c) 2009 Boris Schaeling
0004 // Copyright (c) 2010 Felipe Tanus, Boris Schaeling
0005 // Copyright (c) 2011, 2012 Jeff Flinn, Boris Schaeling
0006 // Copyright (c) 2016 Klemens D. Morgenstern
0007 //
0008 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0009 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0010
0011 #ifndef BOOST_PROCESS_SHELL_PATH_HPP
0012 #define BOOST_PROCESS_SHELL_PATH_HPP
0013
0014 #include <boost/process/detail/config.hpp>
0015 #include <boost/process/detail/traits/wchar_t.hpp>
0016
0017 #if defined(BOOST_POSIX_API)
0018 #include <boost/process/detail/posix/shell_path.hpp>
0019 #elif defined(BOOST_WINDOWS_API)
0020 #include <boost/process/detail/windows/shell_path.hpp>
0021 #endif
0022
0023 /** \file boost/process/shell.hpp
0024  *
0025  *    Header which provides the shell property. This provides the
0026  *    property to launch a process through the system shell.
0027  *    It also allows the user to obtain the shell-path via shell().
0028 \xmlonly
0029 <programlisting>
0030 namespace boost {
0031   namespace process {
0032     <emphasis>unspecified</emphasis> <globalname alt="boost::process::shell">shell</globalname>;
0033   }
0034 }
0035 </programlisting>
0036 \endxmlonly
0037
0038  */
0039
0040 namespace boost { namespace process { namespace detail {
0041
0042
0043 struct shell_
0044 {
0045     constexpr shell_() {}
0046
0047     boost::process::filesystem::path operator()() const
0048     {
0049         return boost::process::detail::api::shell_path();
0050     }
0051     boost::process::filesystem::path operator()(std::error_code & ec) const noexcept
0052     {
0053         return boost::process::detail::api::shell_path(ec);
0054     }
0055 };
0056
0057 template<>
0058 struct is_wchar_t<shell_> : is_wchar_t<boost::process::filesystem::path>
0059 {
0060 };
0061
0062 }
0063 /**
0064 The shell property enables to launch a program through the shell of the system.
0065
0066 \code{.cpp}
0067 system("gcc", shell);
0068 \endcode
0069
0070 The shell argument goes without any expression. The operator() is overloaded, to
0071 obtain the path of the system shell.
0072
0073 \code{.cpp}
0074 auto shell_cmd = shell();
0075 //avoid exceptions
0076 std::error_code ec;
0077 shell_cmd = shell(ec);
0078 \endcode
0079
0080 \attention Launching through the shell will NOT provide proper error handling, i.e.
0081 you will get an error via the return code.
0082
0083 \attention Executing shell commands that incorporate unsanitized input from an untrusted source makes a program vulnerable to shell injection, a serious security flaw which can result in arbitrary command execution. For this reason, the use of `shell` is strongly discouraged in cases where the command string is constructed from external input:
0084
0085 */
0086 constexpr ::boost::process::detail::shell_ shell;
0087
0088 }}
0089
0090
0091
0092 #endif