Solved! The Libraries need to be at the end during the link phase. $ g++ -c -I/usr/include -Iinclude -std=c++0x -o udp_echo_client.o udp_echo_client.cpp $ g++ -o udp_echo_client udp_echo_client.o -L/usr/lib -lboost_filesystem -lboost_system -lpthread works BR Ulf -------- Original Message -------- Subject: Getting ASIO application to link (undefined reference to `boost::system::generic_category()) Date: Tue, 17 Sep 2013 16:58:55 +0200 From: Ulf Samuelsson To: boost-users@lists.boost.org Hi, Trying to get an ASIO example (udp_echo_client) to build on an Ubuntu 12.04 machine. It looks like both 1.46 and 1.48 can be installed. (I have installed 1.48). The libboost*.so all are linked vs 1.48, and the /usr/include/boost/version.hpp contains #define BOOST_LIB_VERSION "1_48" so I think that there should not be a version mismatch, I can build some really simple examples but, as soon as I add "asio" with the statement below, the build fails. using boost::asio::ip::udp; Fiirst problem is that `boost::system::generic_category()' is missing. When I grep the libboost libraries, they are only found in "libboost_[file]system[-mt].so" but these files are included in the link. Searching on Internet, also tells me to link with those libraries, which is not a help. Tried with "-mt" version as well. Added #include #include without any change. What is going on? Running out of ideas... Thanks for any advice. /Ulf Samuelsson ---------------------------------------------------------- g++ -I/usr/include -Iinclude -L/usr/lib -lboost_filesystem -lboost_system -lpthread -std=c++0x -o udp_echo_client udp_echo_client.cpp /tmp/ccu20iRA.o: In function `__static_initialization_and_destruction_0(int, int)': udp_echo_client.cpp:(.text+0x58d): undefined reference to `boost::system::generic_category()' udp_echo_client.cpp:(.text+0x597): undefined reference to `boost::system::generic_category()' udp_echo_client.cpp:(.text+0x5a1): undefined reference to `boost::system::system_category()' /tmp/ccu20iRA.o: In function `boost::system::error_code::error_code()': udp_echo_client.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x10): undefined reference to `boost::system::system_category()' /tmp/ccu20iRA.o: In function `boost::asio::error::get_system_category()': udp_echo_client.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x7): undefined reference to `boost::system::system_category()' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_tss_ptr_create(unsigned int&)': udp_echo_client.cpp:(.text._ZN5boost4asio6detail20posix_tss_ptr_createERj[boost::asio::detail::posix_tss_ptr_create(unsigned int&)]+0x15): undefined reference to `pthread_key_create' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_thread::~posix_thread()': udp_echo_client.cpp:(.text._ZN5boost4asio6detail12posix_threadD2Ev[_ZN5boost4asio6detail12posix_threadD5Ev]+0x1d): undefined reference to `pthread_detach' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_thread::join()': udp_echo_client.cpp:(.text._ZN5boost4asio6detail12posix_thread4joinEv[boost::asio::detail::posix_thread::join()]+0x25): undefined reference to `pthread_join' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_thread::start_thread(boost::asio::detail::posix_thread::func_base*)': udp_echo_client.cpp:(.text._ZN5boost4asio6detail12posix_thread12start_threadEPNS2_9func_baseE[boost::asio::detail::posix_thread::start_thread(boost::asio::detail::posix_thread::func_base*)]+0x24): undefined reference to `pthread_create' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_tss_ptr::context>::~posix_tss_ptr()': udp_echo_client.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceENS4_11thread_infoEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceENS4_11thread_infoEE7contextEED5Ev]+0xf): undefined reference to `pthread_key_delete' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_tss_ptr::context>::operator boost::asio::detail::call_stack::context*() const': udp_echo_client.cpp:(.text._ZNK5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceENS4_11thread_infoEE7contextEEcvPS7_Ev[boost::asio::detail::posix_tss_ptr::context>::operator boost::asio::detail::call_stack::context*() const]+0xf): undefined reference to `pthread_getspecific' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_tss_ptr::context>::~posix_tss_ptr()': udp_echo_client.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_14strand_service11strand_implEhE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_14strand_service11strand_implEhE7contextEED5Ev]+0xf): undefined reference to `pthread_key_delete' /tmp/ccu20iRA.o: In function `boost::asio::detail::posix_tss_ptr::context>::operator=(boost::asio::detail::call_stack::context*)': udp_echo_client.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceENS4_11thread_infoEE7contextEEaSEPS7_[boost::asio::detail::posix_tss_ptr::context>::operator=(boost::asio::detail::call_stack::context*)]+0x16): undefined reference to `pthread_setspecific' collect2: ld returnerade avslutningsstatus 1 make: *** [udp_echo_client] Fel 1 -------------------------------------------------------------- Makefile: ------------------------------------------------------ # Using 1.48.0 in Ubuntu 12.04 BOOST=/usr INCLUDES += -I$(BOOST)/include -Iinclude LIBS +=-L$(BOOST)/lib -lboost_filesystem -lboost_system -lpthread CFLAGS=$(INCLUDES) $(LIBS) -std=c++0x all: udp_echo_client udp_echo_client: udp_echo_client.cpp g++ $(CFLAGS) -o $@ udp_echo_client.cpp clean: rm -f udp_echo_client rm -f *~ -------------------------------------------------------- Code from example: -------------------------------------------------------- // // blocking_udp_echo_client.cpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2013 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // 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) // #include <cstdlib> #include <cstring> #include <iostream> #include using boost::asio::ip::udp; enum { max_length = 1024 }; int main(int argc, char* argv[]) { try { if (argc != 3) { std::cerr << "Usage: blocking_udp_echo_client <host> <port>\n"; return 1; } boost::asio::io_service io_service; udp::socket s(io_service, udp::endpoint(udp::v4(), 0)); udp::resolver resolver(io_service); udp::endpoint endpoint = *resolver.resolve({udp::v4(), argv[1], argv[2]}); std::cout << "Enter message: "; char request[max_length]; std::cin.getline(request, max_length); size_t request_length = std::strlen(request); s.send_to(boost::asio::buffer(request, request_length), endpoint); char reply[max_length]; udp::endpoint sender_endpoint; size_t reply_length = s.receive_from( boost::asio::buffer(reply, max_length), sender_endpoint); std::cout << "Reply is: "; std::cout.write(reply, reply_length); std::cout << "\n"; } catch (std::exception& e) { std::cerr << "Exception: " << e.what() << "\n"; } return 0; }