Trouble using boost, cannot open shared object file

Question

So I'm trying to compile and run a simple boost timer program

#include <iostream>
#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>


int main() {
    using namespace boost::asio;
    io_service io;
    deadline_timer t(io, boost::posix_time::seconds(5));
    t.wait();
    std::cout << "Hello World!" << std::endl;

    return 0;
}

The first thing I tried when compiling this program was to do

g++ -I /home/vagrant/boost_1_60_0 main.cpp

which gave me an error of

/tmp/cc8Ytqko.o: In function `__static_initialization_and_destruction_0(int, int)':
main.cpp:(.text+0xfc): undefined reference to `boost::system::generic_category()'
main.cpp:(.text+0x108): undefined reference to `boost::system::generic_category()'
main.cpp:(.text+0x114): undefined reference to `boost::system::system_category()'
/tmp/cc8Ytqko.o: In function `boost::system::error_code::error_code()':
main.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x17): undefined reference to `boost::system::system_category()'
/tmp/cc8Ytqko.o: In function `boost::asio::error::get_system_category()':
main.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[_ZN5boost4asio5error19get_system_categoryEv]+0x5): undefined reference to `boost::system::system_category()'
collect2: error: ld returned 1 exit status

So then I did some research and it seems I needed to build the boost_system binaries so I went to directory boost was located in and ran

./bootstrap.sh
./b2 --with-system

Then I compiled again

g++ -I /home/vagrant/boost_1_60_0 main.cpp -L/home/vagrant/boost_1_60_0/stage/lib/ -lboost_system

and this didn't give me any error but when I ran the executable

vagrant@vagrant-ubuntu-trusty-64:/vagrant$ ./a.out
./a.out: error while loading shared libraries: libboost_system.so.1.60.0: cannot open shared object file: No such file or directory

Don't really know what I need to do here

Answer 1

liibboost_system.so.1.60.0 cannot be found in the list of directories searched by the dynamic linker. The non-default shared-object location is not stored in the binary by default. The environment variable LD_LIBRARY_PATH can be used to add directories that will be searched before the standard locations:

LD_LIBRARY_PATH=/home/vagrant/boost_1_60_0/stage/lib/ ./a.out

This will only work for the current bash environment, and there are also ways to store the path in the executable so that the environment variable is not needed.