c++ - boost 进程运行 su

Question

我使用 boost 1_65_1 并尝试在 MacOS 上运行一个进程。我的主要进程以 root 身份运行我需要以普通用户身份启动子启动。我的命令行:su user_name -c "full 可执行文件的路径"。当我以 root 身份在终端中运行命令行时，它正常工作。

当我尝试使用 Boost Process 运行它时，进程“su”正在运行但立即退出并出现错误 2。

我运行流程的代码:

void RunProcess(std::string a_PathToExe, std::vector<std::string> a_Args, io_servicePtr a_pIoServicePtr,
                ProcessExitCallBack a_pProcessExitCallBack) {

    Error l_Error;
    std::stringstream l_ShellCommandLine;
    ProcessHandlePtr l_pProcess = NULL;
    boost::process::group l_Group;
    boost::shared_ptr<boost::process::async_pipe> l_PipeOutputStream =
        boost::shared_ptr<boost::process::async_pipe>(new boost::process::async_pipe(*(a_pIoServicePtr.get())));
    boost::shared_ptr<boost::process::async_pipe> l_PipeError =
        boost::shared_ptr<boost::process::async_pipe>(new boost::process::async_pipe(*(a_pIoServicePtr.get())));

    try {

        l_ShellCommandLine << "\"" << a_PathToExe << "\""
                           << " ";
        for (size_t i = 0; i < a_Args.size(); ++i) {
            l_ShellCommandLine << a_Args.at(i) << " ";
        }

        l_pProcess = ProcessHandlePtr(new boost::process::child(
            l_ShellCommandLine.str(), boost::process::std_in.close(),
            boost::process::std_out > *(l_PipeOutputStream.get()), boost::process::std_err > *(l_PipeError.get()),
            *(a_pIoServicePtr.get()), l_Group, boost::process::shell,
            boost::process::on_exit = [](int exit, const std::error_code &ec_in) {
                WRITE_INFO_LOG("The process exit with error %d %s", exit, ec_in.message().c_str());
            }));

        l_PID = l_pProcess->id();
        WaiteForProcessToExit(l_pProcess, l_PipeOutputStream, l_PipeError, a_pProcessExitCallBack);
    }

    catch (std::exception &e) {

    } catch (...) {
    }
    return;
}

void WaiteForProcessToExit(ProcessHandlePtr a_pProcessHandle,
                           boost::shared_ptr<boost::process::async_pipe> a_PipeOutputStream,
                           boost::shared_ptr<boost::process::async_pipe> a_PipeError,
                           ProcessExitCallBack a_pProcessExitCallBack) {

    std::array<char, 1024> buffer = std::array<char, 1024>{};
    a_PipeOutputStream->async_read_some(
        boost::process::buffer(buffer), [=](boost::system::error_code ec, size_t transferre) {
            if (transferre > 0) {
                std::string Line = std::string(buffer.data());
                WRITE_INFO_LOG("%s", Line.c_str());
            }

            if (ec != 0) {

                WRITE_INFO_LOG("The Process %d has exit with error code %d", a_pProcessHandle->id(), ec);
                if (a_pProcessExitCallBack != NULL) {
                    a_pProcessExitCallBack(a_pProcessHandle->id(), Error());
                }
            } else {
                WaiteForProcessToExit(a_pProcessHandle, a_PipeOutputStream, a_PipeError, a_pProcessExitCallBack);
            }
        });
}

为什么子进程没有运行？提前致谢

Answer 1

首先，您没有显示足够的代码。

其次，如果你使用 su，你不应该要求 bp::shell。

第三，该代码看起来像一个 C 编译器跑掉了。为什么这么复杂？为什么全是动态内存管理？为什么要异步，如果您所做的只是等待完成？

这是我的简化版本，它对我有用。或许您可以找到您之前所做的不同的取景器细节:

同步，C++:

Live On Coliru

#include <iostream>
#include <boost/asio.hpp>
#include <boost/process.hpp>
#include <boost/process/async.hpp>

namespace bp = boost::process;

struct ProcessResult {
    std::string out, err;
    int exitcode;
};

ProcessResult RunProcess(std::string exe, std::vector<std::string> args, boost::asio::io_service& io) {
    std::future<std::string> out, err;
    bp::group group;

    bp::child child(
        bp::search_path(exe), args, bp::std_in.close(), bp::std_out > out, bp::std_err > err, io, group
    );

    child.wait();
    return { out.get(), err.get(), child.exit_code() };
}

int main() {
    boost::asio::io_service io;

    // keep work to avoid io.run to complete early
    auto work = boost::asio::make_work_guard(io);
    std::thread io_thread([&io] { io.run(); });

    auto pstree = RunProcess("su", { "sehe", "-c", "/usr/bin/free" }, io);

    std::cout << "Exitcode: " << pstree.exitcode << "\n";
    std::cout << "Output: " << pstree.out << "\n";
    std::cout << "Error: " << pstree.err << "\n";

    work.reset(); // allow service to complete
    io_thread.join();
}

打印(以 root 身份运行时):

Exitcode: 0
Output:               total        used        free      shared  buff/cache   available
Mem:       32832516    21846896     2486924     2963636     8498696     5595284
Swap:             0           0           0

Error: 

当不以 root 身份运行时:

Exitcode: 1
Output: 
Error: su: must be run from a terminal

异步

您仍然可以将异步与 C++ 风格结合起来。参见例如

• Unexpected end of file while reading mpstat output with BOOST ASIO async_read_until
• Read child process stdout in a separate thread with BOOST process
• simultaneous read and write to child's stdio using boost.process
• Boost::process output blank lines