Hi,
I need to check if a url is valid or not using regex.
I have installed everything following the tutorial.
but still I am getting the following  error.I dont know how to build regex programs.Can you please guide me.

Regards,
Jyothsna
./infoextractor.o: In function `bool boost::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)':
/usr/include/boost/regex/v4/regex_match.hpp:50: undefined reference to `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::match()'
./infoextractor.o: In function `boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::assign(char const*, char const*, unsigned int)':
/usr/include/boost/regex/v4/basic_regex.hpp:425: undefined reference to `boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::do_assign(char const*, char const*, unsigned int)'
./infoextractor.o: In function `perl_matcher':
/usr/include/boost/regex/v4/perl_matcher.hpp:366: undefined reference to `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)'
./infoextractor.o: In function `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::unwind_extra_block(bool)':
/usr/include/boost/regex/v4/perl_matcher_non_recursive.hpp:1113: undefined reference to `boost::re_detail::put_mem_block(void*)'
./infoextractor.o: In function `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::match_match()':
/usr/include/boost/regex/v4/perl_matcher_non_recursive.hpp:969: undefined reference to `boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >::maybe_assign(boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > const&)'
./infoextractor.o: In function `void boost::re_detail::raise_error<boost::regex_traits_wrapper<boost::regex_traits<char, boost::cpp_regex_traits<char> > > >(boost::regex_traits_wrapper<boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::error_type)':
/usr/include/boost/regex/pattern_except.hpp:75: undefined reference to `boost::re_detail::raise_runtime_error(std::runtime_error const&)'
./infoextractor.o: In function `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::extend_stack()':
/usr/include/boost/regex/v4/perl_matcher_non_recursive.hpp:213: undefined reference to `boost::re_detail::get_mem_block()'
./infoextractor.o: In function `boost::cpp_regex_traits<char>::transform(char const*, char const*) const':
/usr/include/boost/regex/v4/cpp_regex_traits.hpp:906: undefined reference to `boost::re_detail::cpp_regex_traits_implementation<char>::transform(char const*, char const*) const'
./infoextractor.o: In function `boost::cpp_regex_traits<char>::transform_primary(char const*, char const*) const':
/usr/include/boost/regex/v4/cpp_regex_traits.hpp:910: undefined reference to `boost::re_detail::cpp_regex_traits_implementation<char>::transform_primary(char const*, char const*) const'
./infoextractor.o: In function `boost::re_detail::cpp_regex_traits_implementation<char>::error_string(boost::regex_constants::error_type) const':
/usr/include/boost/regex/v4/cpp_regex_traits.hpp:440: undefined reference to `boost::re_detail::get_default_error_string(boost::regex_constants::error_type)'
/usr/include/boost/regex/v4/cpp_regex_traits.hpp:442: undefined reference to `boost::re_detail::get_default_error_string(boost::regex_constants::error_type)'
collect2: ld returned 1 exit status
make: *** [Emailparser] Error 1