我正在尝试学习一点点C和Boost.Asio.我正在尝试编译以下代码示例：
@H_404_2@#include <iostream>
#include <boost/array.hpp>
#include <boost/asio.hpp>
using boost::asio::ip::tcp;
int main(int argc,char* argv[])
{
try
{
if (argc != 2)
{
std::cerr << "Usage: client <host>" << std::endl;
return 1;
}
boost::asio::io_service io_service;
tcp::resolver resolver(io_service);
tcp::resolver::query query(argv[1],"daytime");
tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);
tcp::resolver::iterator end;
tcp::socket socket(io_service);
boost::system::error_code error = boost::asio::error::host_not_found;
while (error && endpoint_iterator != end)
{
socket.close();
socket.connect(*endpoint_iterator++,error);
}
if (error)
throw boost::system::system_error(error);
for (;;)
{
boost::array<char,128> buf;
boost::system::error_code error;
size_t len = socket.read_some(boost::asio::buffer(buf),error);
if (error == boost::asio::error::eof)
break; // Connection closed cleanly by peer.
else if (error)
throw boost::system::system_error(error); // Some other error.
std::cout.write(buf.data(),len);
}
}
catch (std::exception& e)
{
std::cerr << e.what() << std::endl;
}
return 0;
}
使用以下命令行：
@H_404_2@g++ -I /usr/local/boost_1_42_0 a.cpp它引起了一个不清楚的错误：
@H_404_2@/tmp/ccCv9ZJA.o: In function `__static_initialization_and_destruction_0(int,int)': a.cpp:(.text+0x654): undefined reference to `boost::system::get_system_category()' a.cpp:(.text+0x65e): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x668): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x672): undefined reference to `boost::system::get_generic_category()' a.cpp:(.text+0x67c): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::system::error_code::error_code()': a.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x10): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::asio::error::get_system_category()': a.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x7): undefined reference to `boost::system::get_system_category()' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_thread::~posix_thread()': a.cpp:(.text._ZN5boost4asio6detail12posix_threadD2Ev[_ZN5boost4asio6detail12posix_threadD5Ev]+0x1d): undefined reference to `pthread_detach' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_thread::join()': a.cpp:(.text._ZN5boost4asio6detail12posix_thread4joinEv[boost::asio::detail::posix_thread::join()]+0x25): undefined reference to `pthread_join' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> > >::context>::~posix_tss_ptr()': a.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEED5Ev]+0xf): undefined reference to `pthread_key_delete' /tmp/ccCv9ZJA.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> > >::context>::posix_tss_ptr()': a.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEEC2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceINS1_13epoll_reactorILb0EEEEEE7contextEEC5Ev]+0x22): undefined reference to `pthread_key_create' collect2: ld returned 1 exit status我该如何解决？
