bp :: child * proc = new bp :: child（“a.out”，bp :: std_out＆gt; stdout，bp :: std_err＆gt; stderr）;
我正在使用Linux平台。谢谢。目前还没有方法可以做到这一点。
我曾经尝试过添加补丁来实现它，但是遇到了一些问题，测试时间不够。我可以分享这个补丁，但你需要自己测试。
请注意，以下所有内容都是基于POSIX系统。
最简单的方法似乎是关闭所有非标准fd，没有例外：
struct close_fds : bp::extend::handler {
template <typename Executor>
void on_exec_setup(Executor& /*ex*/) {
// TODO implemented smarter - below meddles with the library internals
int maxfd=sysconf(_SC_OPEN_MAX);
for(int fd=3; fd<maxfd; fd++) {
::close(fd);
}
}
};
bp::child x(..., close_fds{});
这样做是行不通的
首先，Boost Process 内部使用强制的父子管道进行内部通信（例如错误处理/报告）。我们没有考虑到它，并且无法预测涉及哪个 fd 值，因此让我们转向更复杂的想法：
更智能的设置将考虑到 Boost Process 所涉及的任何 fds。这包括上述管道以及可能是其他进程启动参数指定的重定向结果的任何其他 fds。
以下是我准备好的补丁
同样，这未经测试。该补丁 最初针对 Boost 1.63，当时还没有官方的 Boost Process 发布, 但我“最近”（4月份）将其移植到了 Boost 1.66。
使用方式与上述类似：
bp::child x(..., bp::posix::fd.restrict_inherit()); };
From 45c46a3d9ed42278af97e6ca11474bfbddf3ffb4 Mon Sep 17 00:00:00 2001
From: Seth Heeren <heeren@tracksinspector.com>
Date: Tue, 10 Apr 2018 02:48:27 +0200
Subject: [PATCH] fd_restrict prototype
---
boost/process/detail/posix/executor.hpp | 16 ++-
boost/process/detail/posix/fd.hpp | 8 ++
boost/process/detail/posix/fd_restrict.hpp | 154 +++++++++++++++++++++++++
boost/process/detail/posix/file_descriptor.hpp | 7 ++
4 files changed, 181 insertions(+), 4 deletions(-)
create mode 100644 boost/process/detail/posix/fd_restrict.hpp
diff --git a/boost/process/detail/posix/executor.hpp b/boost/process/detail/posix/executor.hpp
index b3781f2..0a7c446 100644
--- a/boost/process/detail/posix/executor.hpp
+++ b/boost/process/detail/posix/executor.hpp
@@ -15,6 +15,7 @@
#include <boost/process/pipe.hpp>
#include <boost/process/detail/posix/basic_pipe.hpp>
#include <boost/process/detail/posix/use_vfork.hpp>
+#include <boost/process/detail/posix/file_descriptor.hpp>
#include <boost/fusion/algorithm/iteration/for_each.hpp>
#include <cstdlib>
#include <sys/types.h>
@@ -45,7 +46,7 @@ inline int execvpe(const char* filename, char * const arg_list[], char* env[])
if (e != nullptr)
{
- std::vector<std::string> path;
+ std::vector<std::string> path;
boost::split(path, *e, boost::is_any_of(":"));
for (const std::string & pp : path)
@@ -157,13 +158,13 @@ struct on_fork_success_t
};
template<typename Executor> on_setup_t <Executor> call_on_setup (Executor & exec) {return exec;}
-template<typename Executor> on_error_t <Executor> call_on_error (Executor & exec, const std::error_code & ec)
+template<typename Executor> on_error_t <Executor> call_on_error (Executor & exec, const std::error_code & ec)
{
return on_error_t<Executor> (exec, ec);
}
template<typename Executor> on_success_t<Executor> call_on_success(Executor & exec) {return exec;}
-template<typename Executor> on_fork_error_t <Executor> call_on_fork_error (Executor & exec, const std::error_code & ec)
+template<typename Executor> on_fork_error_t <Executor> call_on_fork_error (Executor & exec, const std::error_code & ec)
{
return on_fork_error_t<Executor> (exec, ec);
}
@@ -330,6 +331,12 @@ public:
}
void set_error(const std::error_code &ec, const std::string &msg) {set_error(ec, msg.c_str());};
+ // customization point for fd_restrict
+ template <typename OutputIterator>
+ friend void collect_filedescriptors(executor const& me, OutputIterator& outit) {
+ // always protect the write end of the parent/child pipe
+ *outit++ = me._pipe_sink;
+ }
};
template<typename Sequence>
@@ -380,6 +387,7 @@ child executor<Sequence>::invoke(boost::mpl::false_, boost::mpl::false_)
return child();
}
_ec.clear();
+ _pipe_sink = p[1];
boost::fusion::for_each(seq, call_on_setup(*this));
if (_ec)
@@ -391,6 +399,7 @@ child executor<Sequence>::invoke(boost::mpl::false_, boost::mpl::false_)
this->pid = ::fork();
if (pid == -1)
{
+ _pipe_sink = -1;
_ec = boost::process::detail::get_last_error();
_msg = "fork() failed";
boost::fusion::for_each(seq, call_on_fork_error(*this, _ec));
@@ -400,7 +409,6 @@ child executor<Sequence>::invoke(boost::mpl::false_, boost::mpl::false_)
}
else if (pid == 0)
{
- _pipe_sink = p[1];
::close(p[0]);
boost::fusion::for_each(seq, call_on_exec_setup(*this));
diff --git a/boost/process/detail/posix/fd.hpp b/boost/process/detail/posix/fd.hpp
index 51790c3..f759d9e 100644
--- a/boost/process/detail/posix/fd.hpp
+++ b/boost/process/detail/posix/fd.hpp
@@ -11,6 +11,7 @@
#define BOOST_PROCESS_DETAIL_POSIX_FD_HPP
#include <boost/process/detail/posix/handler.hpp>
+#include <boost/process/detail/posix/fd_restrict.hpp>
#include <unistd.h>
namespace boost { namespace process { namespace detail { namespace posix {
@@ -68,6 +69,12 @@ public:
}
private:
+ // customization point for fd_restrict
+ template <typename OutputIterator>
+ friend void collect_filedescriptors(bind_fd_ const& bind_fd, OutputIterator& outit) {
+ *outit++ = bind_fd.id_;
+ }
+
int id_;
FileDescriptor fd_;
};
@@ -84,6 +91,7 @@ struct fd_
template <class FileDescriptor>
bind_fd_<FileDescriptor> bind(int id, const FileDescriptor & fd) const {return {id, fd};}
+ fd_restrict::property_<> restrict_inherit(size_t capacity = 128) const {return {capacity};}
};
diff --git a/boost/process/detail/posix/fd_restrict.hpp b/boost/process/detail/posix/fd_restrict.hpp
new file mode 100644
index 0000000..71c6c7d
--- /dev/null
+++ b/boost/process/detail/posix/fd_restrict.hpp
@@ -0,0 +1,154 @@
+// Copyright (c) 2017 Seth Heeren
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_PROCESS_DETAIL_POSIX_FD_RESTRICT_HPP
+#define BOOST_PROCESS_DETAIL_POSIX_FD_RESTRICT_HPP
+
+#include <boost/process/detail/posix/handler.hpp>
+#include <unistd.h>
+
+namespace boost { namespace process { namespace detail { namespace posix { namespace fd_restrict {
+ // customization point for (custom) properties that need to protect fds
+ template <typename Property, typename OutputIterator>
+ void collect_filedescriptors(Property const& /*property*/, OutputIterator& /*outit*/) {
+ // primary template
+ }
+
+ // polymorphic function object for ADL dispatch
+ template <typename OutputIterator>
+ struct collect_fd_f {
+ OutputIterator mutable _outit;
+
+ template <typename Property>
+ void operator()(Property const& property) const {
+ using boost::process::detail::posix::fd_restrict::collect_filedescriptors; // ADL desired
+ collect_filedescriptors(property, _outit);
+ }
+ };
+
+ // launch property
+ template <typename=void>
+ struct property_ : handler_base_ext
+ {
+ public:
+ property_(size_t capacity) {
+ // reserve to avoid allocations between fork/exec which may
+ // deadlock with threads
+ _protected_fds.reserve(capacity);
+ }
+
+ template <class PosixExecutor>
+ void on_exec_setup(PosixExecutor& exec) const
+ {
+ _protected_fds.resize(0);
+ auto outit = back_inserter(_protected_fds);
+ collect_fd_f<decltype(outit)> visit{outit};
+
+ visit(exec);
+ boost::fusion::for_each(exec.seq, visit);
+
+ auto begin = _protected_fds.begin(), end = _protected_fds.end();
+ std::sort(begin, end);
+
+ for(int fd=0, maxfd=sysconf(_SC_OPEN_MAX); fd<maxfd; ++fd) {
+ if (!std::binary_search(begin, end, fd))
+ ::close(fd);
+ }
+ }
+
+ private:
+ std::vector<int> mutable _protected_fds;
+ };
+
+}}}}}
+
+/*
+ * Non-intrusive instrumentation of existing POSIX properties that require filedescriptors
+ *
+ * All of these could be done with an inline `friend` definition, like above.
+ *
+ * For now I prefer to keep them separate so that
+ *
+ * - upstream changes merge cleanly
+ * - interface changes in fd_restrict can more easily be applied consistently in 1 file
+ *
+ * Only bind_fd_ and filedescriptor need friend access, so cannot usefully be kept separate.
+ */
+
+#include <boost/process/detail/posix/async_in.hpp>
+#include <boost/process/detail/posix/async_out.hpp>
+#include <boost/process/detail/posix/null_in.hpp>
+#include <boost/process/detail/posix/null_out.hpp>
+#include <boost/process/detail/posix/file_in.hpp>
+#include <boost/process/detail/posix/file_out.hpp>
+#include <boost/process/detail/posix/pipe_in.hpp>
+#include <boost/process/detail/posix/pipe_out.hpp>
+
+namespace boost { namespace process { namespace detail { namespace posix {
+
+template<typename... Ts, typename OutputIterator>
+void collect_filedescriptors(async_in_buffer<Ts...> const&, OutputIterator& outit) {
+ *outit++ = STDIN_FILENO;
+}
+
+template<int p1, int p2, typename... Ts, typename OutputIterator>
+void collect_filedescriptors(async_out_buffer<p1, p2, Ts...> const&, OutputIterator& outit) {
+ if (p1==1||p2==1) *outit++ = STDOUT_FILENO;
+ if (p1==2||p2==2) *outit++ = STDERR_FILENO;
+}
+
+template<int p1, int p2, typename... Ts, typename OutputIterator>
+void collect_filedescriptors(async_out_future<p1, p2, Ts...> const&, OutputIterator& outit) {
+ if (p1==1||p2==1) *outit++ = STDOUT_FILENO;
+ if (p1==2||p2==2) *outit++ = STDERR_FILENO;
+}
+
+template<typename OutputIterator>
+void collect_filedescriptors(file_in const&, OutputIterator& outit) {
+ *outit++ = STDIN_FILENO;
+}
+
+template<int p1, int p2, typename OutputIterator>
+void collect_filedescriptors(file_out<p1, p2> const&, OutputIterator& outit) {
+ if (p1==1||p2==1) *outit++ = STDOUT_FILENO;
+ if (p1==2||p2==2) *outit++ = STDERR_FILENO;
+}
+
+template<typename OutputIterator>
+void collect_filedescriptors(null_in const&, OutputIterator& outit) {
+ *outit++ = STDIN_FILENO;
+}
+
+template<int p1, int p2, typename OutputIterator>
+void collect_filedescriptors(null_out<p1, p2> const&, OutputIterator& outit) {
+ if (p1==1||p2==1) *outit++ = STDOUT_FILENO;
+ if (p1==2||p2==2) *outit++ = STDERR_FILENO;
+}
+
+template<typename OutputIterator>
+void collect_filedescriptors(pipe_in const&, OutputIterator& outit) {
+ *outit++ = STDIN_FILENO;
+}
+
+template<typename OutputIterator>
+void collect_filedescriptors(async_pipe_in const&, OutputIterator& outit) {
+ *outit++ = STDIN_FILENO;
+}
+
+template<int p1, int p2, typename OutputIterator>
+void collect_filedescriptors(pipe_out<p1, p2> const&, OutputIterator& outit) {
+ if (p1==1||p2==1) *outit++ = STDOUT_FILENO;
+ if (p1==2||p2==2) *outit++ = STDERR_FILENO;
+}
+
+template<int p1, int p2, typename OutputIterator>
+void collect_filedescriptors(async_pipe_out<p1, p2> const&, OutputIterator& outit) {
+ if (p1==1||p2==1) *outit++ = STDOUT_FILENO;
+ if (p1==2||p2==2) *outit++ = STDERR_FILENO;
+}
+
+}}}}
+
+#endif
diff --git a/boost/process/detail/posix/file_descriptor.hpp b/boost/process/detail/posix/file_descriptor.hpp
index 0dcb99c..0cfcfd1 100644
--- a/boost/process/detail/posix/file_descriptor.hpp
+++ b/boost/process/detail/posix/file_descriptor.hpp
@@ -53,6 +53,13 @@ struct file_descriptor
int handle() const { return _handle;}
private:
+ // customization point for fd_restrict
+ template <typename OutputIterator>
+ friend void collect_filedescriptors(file_descriptor const& property_, OutputIterator& outit) {
+ if (-1 != property_._handle)
+ *outit++ = property_._handle;
+ }
+
static int create_file(const char* name, mode_t mode )
{
switch(mode)
--
2.16.2