Undefined reference to curlpp using code::blocks on kubuntu - c++

Question

I have a problem with curlpp library. I'll explain the steps that I followed.
Step 1: download and installation
download website: Download
$./configure
$make
$sudo make install
curlpp header files are located in /usr/local/include/
curlpp library files are located in /usr/local/lib/
Step 2: I used the following code:
#include <curlpp/cURLpp.hpp>
#include <curlpp/Easy.hpp>
#include <curlpp/Options.hpp>
#include <curlpp/Exception.hpp>
using namespace std;
int main()
{
char *url = (char*) "http://dbpedia.org/sparql";
string queryString = "PREFIX dbp: <http://dbpedia.org/resource/> "
"PREFIX dbp2: <http://dbpedia.org/ontology/> "
"SELECT ?abstract "
"WHERE { "
"dbp:Nikola_Tesla dbp2:abstract ?abstract . "
"FILTER langMatches(lang(?abstract), 'en')"
"}";
try
{
curlpp::Easy request;
string parameters = "query=" + curlpp::escape(queryString);
request.setOpt(new curlpp::options::Url(url));
request.setOpt(new curlpp::options::Verbose(true));
request.setOpt(new curlpp::options::PostFields(parameters));
request.perform();
}
catch (curlpp::RuntimeError & e)
{
std::cout << e.what() << std::endl;
}
catch (curlpp::LogicError & e)
{
std::cout << e.what() << std::endl;
}
return 0;
}//end function main
Errors
Undefined reference to curlpp ::Easy:Easy()
Undefined reference to curlpp ::escape (const std :: string &)
Undefined reference to curlpp ::Easy::setopt (curlpp OptionBase :: *)
Undefined reference to curlpp curlpp::Easy::setopt(curlpp OptionBase:: *)
etc.
After adding -lcurlpp as the picture shows: I got the following errors:
g++ -LSQLiteCpp-master/debug -o bin/Debug/EntityLinking
obj/Debug/DataLoader.o obj/Debug/Entity.o obj/Debug/Fact.o
obj/Debug/FactClass.o obj/Debug/Link.o obj/Debug/main.o
obj/Debug/ManageDb.o obj/Debug/SQLiteCpp-master/sqlite3/sqlite3.o
obj/Debug/tinyxml/tinystr.o obj/Debug/tinyxml/tinyxml.o
obj/Debug/tinyxml/tinyxmlerror.o obj/Debug/tinyxml/tinyxmlparser.o
-lpthread -ldl -lcurlpp SQLiteCpp-master/debug/libSQLiteCpp.a /usr/bin/ld: obj/Debug/main.o: référence au symbole non défini
«curl_easy_setopt##CURL_OPENSSL_3»
//usr/lib/x86_64-linux-gnu/libcurl.so.4: error adding symbols: DSO
missing from command line collect2: error: ld returned 1 exit status
Process terminated with status 1 (0 minute(s), 0 second(s)) 0
error(s), 0 warning(s) (0 minute(s), 0 second(s))

Answer 1

You need to link with -lcurlpp when compiling & linking your code.

Answer 2

Using Eclipse, I never got curlpp example01 working. Even after trying to set up the linkers and the includes. But I was able to compile it from a terminal:
g++ -o exe_name exe_name.cpp -L/usr/local/lib -lcurl -lcurlpp -I/usr/local/include
So I would suggest trying the terminal if Eclipse doesn't work for you.