cannot link boost.system in makefile

Question

Just asked a question about linking Boost libraries in the make file. Thanks to those who helped with that. I ended up with this:

accesstimer: acctime.o bentimer.o
    g++ -L/usr/local/boost/boost_1_39_0/stage/lib -lboost_system -lboost_filesystem   acctime.o bentimer.o -o accesstimer   

acctime.o: acctime.cpp bentimer.h
    g++ -I /usr/local/boost/boost_1_39_0 -c acctime.cpp 

bentimer.o: bentimer.cpp bentimer.h
    g++ -c bentimer.cpp 

My problem now is that boost.filesystem requires boost.system and the above make file can't find boost.system.

I got the name for boost.filesystem by looking in the stage/lib dir and removing the lib and trailing section of the file name (libboost_filesystem-gcc41-mt.a). As you can see above I've done the same with libboost_system-gcc41-mt.a and come up with boost_system but it can't be found.

Does anyone know how I would link boost.system?

Thanks Uncle zeive, that's worked but as soon as I try to use one of the filesystem keywords (e.g. exists) I get this:

g++ -I /usr/local/boost/boost_1_39_0 -c acctime.cpp
In file included from acctime.cpp:5:
bentimer.h:2:19: warning: extra tokens at end of #ifndef directive
bentimer.h:11:18: warning: extra tokens at end of #ifdef directive
bentimer.h:28:3: warning: no newline at end of file
g++ -L/usr/local/boost/boost_1_39_0/stage/lib -lboost_system-gcc41-mt -lboost_filesystem   acctime.o bentimer.o -o accesstimer
acctime.o: In function `boost::enable_if<boost::filesystem::is_basic_path<boost::filesystem::basic_path<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::filesystem::path_traits> >, bool>::type boost::filesystem::exists<boost::filesystem::basic_path<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::filesystem::path_traits> >(boost::filesystem::basic_path<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::filesystem::path_traits> const&)':
acctime.cpp:(.text._ZN5boost10filesystem6existsINS0_10basic_pathISsNS0_11path_traitsEEEEENS_9enable_ifINS0_13is_basic_pathIT_EEbE4typeERKS7_[boost::enable_if<boost::filesystem::is_basic_path<boost::filesystem::basic_path<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::filesystem::path_traits> >, bool>::type boost::filesystem::exists<boost::filesystem::basic_path<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::filesystem::path_traits> >(boost::filesystem::basic_path<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::filesystem::path_traits> const&)]+0x35): undefined reference to `boost::filesystem::detail::status_api(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, boost::system::error_code&)'
collect2: ld returned 1 exit status
make: *** [accesstimer] Error 1

Do you know wjat I'm doing wrong here?

Now I've added the -I boost root link to the first link command it builds fine:

accesstimer: acctime.o bentimer.o
    g++ -L/usr/local/boost/boost_1_39_0/stage/lib -lboost_system-gcc41-mt -lboost_filesystem-gcc41-mt  -I /usr/local/boost/boost_1_39_0 acctime.o bentimer.o -o accesstimer     

acctime.o: acctime.cpp bentimer.h
    g++ -I /usr/local/boost/boost_1_39_0 -c acctime.cpp 

bentimer.o: bentimer.cpp bentimer.h
    g++ -c bentimer.cpp 

But when I execute I get:

./accesstimer: error while loading shared libraries: libboost_system-gcc41-mt-1_39.so.1.39.0: cannot open shared object file: No such file or directory

That file is present but its not picking it up.

Answer 1

Actually you shouldn't remove the entire trailing part, only the extension:

-lboost_system-gcc41-mt

The same goes for boost_filesystem:

-lboost_filesystem-gcc41-mt

Answer 2

The answer for me, hopefully it'll help someone else was as follows: I was having problems linking, the good folk on here got me putting the right stuff in my make file but I was still getting:

./accesstimer: error while loading shared libraries: libboost_system-gcc41-mt-1_39.so.1.39.0: cannot open shared object file: No such file or directory

The solution was to just execute:

ldconfig

On my Linux machine that I had just installed Boost on and built the filesytem libraries. I am assuning that since ldconfig needed to be run for my system to pick up the new libraries I had installed. It now works.