[Boost-users] Help needed with boost::process::child and mysql cli

15 Oct 2019

      Hi,

Im use boost::process::child to create a mysql cli child process to import sql file.
Normally im use this command:
/usr/bin/mysql mysql -h127.0.0.1 -utestuser --password='!@#QWE123qwe' -P3306 --default-character-set=utf8mb4 --max-allowed-packet=1GB < /root/create_db.sql
It’s worked well in bash.

But when use boost::process::child, std_err report ERROR 1045 (28000): Access denied for user 'testuser'@'localhost' (using password: YES).
Is there any bugs in my code?

Os: ubuntu 18.04 LTS
Boost: 1.71.0
MySql:5.7.27

Create_db.sql:
DROP DATABASE IF EXISTS test_db;
CREATE DATABASE test_db;

Thanks

[code]
#include <iostream>

#include <boost/algorithm/string/join.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/process.hpp>

using namespace boost::process;
using namespace boost::iostreams;
using namespace boost::asio;

std::string SearchExecutableInPath(std::string const& filename) {
   try {
      return search_path(filename).generic_string();
   }
   catch (...) {
      return "";
   }
}

int RunProcess(
   std::string const& executable,
   std::vector<std::string> const& args,
   std::string input_file_path
) {
   io_context ioCtx;

   auto work = make_work_guard(ioCtx);

   std::thread ioThread([&ioCtx] {
      ioCtx.run();
   });

   std::future<std::string> dataOut, dataErr;

   child c;

   if (!input_file_path.empty()) {
      c = child(
         boost::filesystem::absolute(executable),
         boost::process::args(args),
         std_out > dataOut,
         std_err > dataErr,
         std_in < boost::filesystem::absolute(input_file_path),
         ioCtx
      );
   }
   else {
      c = child(
         boost::filesystem::absolute(executable),
         boost::process::args(args),
         std_out > dataOut,
         std_err > dataErr,
         std_in.close(),
         ioCtx
      );
   }

   c.wait();

   int result = c.exit_code();

   std::string output = dataOut.get();
   std::string error = dataErr.get();

   if (!output.empty()) {
      std::cout << output << std::endl;
   }

   if (!error.empty()) {
      std::cout << error << std::endl;
   }

   work.reset();
   ioThread.join();

   return result;
}

int main()
{
   // /usr/bin/mysql mysql -h127.0.0.1 -utestuser --password='!@#QWE123qwe' -P3306 --default-character-set=utf8mb4 --max-allowed-packet=1GB < /root/create_db.sql

   std::vector<std::string> args;
   args.reserve(8);

   // mysql cli
   args.push_back("mysql");

   // connection info
   args.push_back("-h127.0.0.1");
   args.push_back("-utestuser");
   args.push_back("--password='!@#QWE123qwe'");
   args.push_back("-P3306");

   // encoding
   args.push_back("--default-character-set=utf8mb4");

   // maybe large sql file
   args.push_back("--max-allowed-packet=1GB");

   int const ret = RunProcess(
      SearchExecutableInPath("mysql"),
      args,
      "/root/create_db.sql");

   std::cout << "ret code: " << ret << std::endl;

    return 0;
}
[/code]

[Boost-users] Help needed with boost::process::child and mysql cli

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