Here's my code. I'm just testing Boost::process so I'll be able to use it if/when I need to. I don't know why I'm getting the linking error that I am getting. I'm a rather novice C++ programmer. I know the concepts, but I make frequent errors in practice and am bad at debugging. I appreciate any help I can get with this.
#include<iostream>
#include<boost/process.hpp>
#include<boost/iostreams/device/file_descriptor.hpp>
namespace bp = ::boost::process;
namespace bpi = ::boost::process::initializers;
namespace bio = ::boost::iostreams;
int main(int argc, char *argv[])
{
bp::pipe p = bp::create_pipe();
bio::file_descriptor_sink sink(p.sink, bio::close_handle);
bp::execute(
bpi::run_exe("/usr/bin/ls"),
bpi::bind_stdout(sink)
);
return(0);
}
And here is my error…
/tmp/cc7cmrV8.o: In function `main':
test.cpp:(.text+0x2b): undefined reference to `boost::iostreams::file_descriptor_sink::file_descriptor_sink(int, boost::iostreams::file_descriptor_flags)'
/tmp/cc7cmrV8.o: In function `boost::process::posix::initializers::bind_stdout::bind_stdout(boost::iostreams::file_descriptor_sink const&)':
test.cpp:(.text._ZN5boost7process5posix12initializers11bind_stdoutC2ERKNS_9iostreams20file_descriptor_sinkE[_ZN5boost7process5posix12initializers11bind_stdoutC5ERKNS_9iostreams20file_descriptor_sinkE]+0x2b): undefined reference to `boost::iostreams::file_descriptor_sink::file_descriptor_sink(boost::iostreams::file_descriptor_sink const&)'
/tmp/cc7cmrV8.o: In function `void boost::process::posix::initializers::bind_stdout::on_exec_setup<boost::process::posix::executor>(boost::process::posix::executor&) const':
test.cpp:(.text._ZNK5boost7process5posix12initializers11bind_stdout13on_exec_setupINS1_8executorEEEvRT_[_ZNK5boost7process5posix12initializers11bind_stdout13on_exec_setupINS1_8executorEEEvRT_]+0x18): undefined reference to `boost::iostreams::file_descriptor::handle() const'
collect2: error: ld returned 1 exit status
Platform: Linux 64-bit
Boost: 1.55 (installed via pacman)
Boost::process: 0.5
Compile command: g++ -Wall test.cpp -o spegh.elf -lboost_system
A simple search threw me at -This-.
Seeing you posted your compile command, I'm guessing you are simply missing -lboost_iostreams in your linker settings.
Related
I have created a simple C++ application. I can compile it, and it works fine. But now I need to load the library dynamically, and I have added dlfnc.h to my project and added some more code:
#include <iostream>
#include <dlfcn.h>
void *mylib;
int eret;
using namespace std;
int main() {
mylib = dlopen("mylib.so", RTLD_LOCAL | RTLD_LAZY);
eret = dlclose(mylib);
cout << "!!!Hello, World!!!" << endl; // Prints !!!Hello, World!!!
return 0;
}
Compiling:
cd ~/workspace/LinuxGcc/src
g++ LinuxGcc.cpp
And I got a compilation error:
/tmp/ccxTLiGY.o: In function `main':
LinuxGcc.cpp:(.text+0xf): undefined reference to `dlopen'
LinuxGcc.cpp:(.text+0x25): undefined reference to `dlclose'
collect2: error: ld returned 1 exit status
dlfcn.h exist in /usr/include/.
Where is the problem?
From dlopen(3):
Link with -ldl.
so
g++ LinuxGcc.cpp -ldl
will be OK.
The solution is very simple. Add the -ldl flag for linking.
In case of the Bazel build system, linkopts = ['-ldl'].
I am trying to define a macro for the source file from the command line on an ubuntu system using the -D flag .
The source file is:
#include<iostream>
using namespace std;
int factorial(int n){
if(n!=1){
return(n * factorial(n-1));
}
else return 1;
#ifdef DEEPAK
cout<<"hello"<<endl;
#endif
}
int main()
{
factorial(4);
return(0);
}
The command I am typing is:
gcc -Wall -DDEEPAK factorial.cpp -o main
BUT, I am getting the error:
/tmp/cc4Ii5l2.o: In function `__static_initialization_and_destruction_0(int, int)':
factorial.cpp:(.text+0x63): undefined reference to `std::ios_base::Init::Init()'
factorial.cpp:(.text+0x72): undefined reference to `std::ios_base::Init::~Init()'
collect2: error: ld returned 1 exit status
Any help would be deeply appreciated. Thanks.
You should use g++ instead of gcc in the command, because gcc doesn't link to the C++ STL by default, and hence it gives an undefined reference to std::ios_base.
g++ -Wall -DDEEPAK factorial.cpp -o main
I am trying to get OGDF working to see if it is suitable for my project, but I am having trouble with a sample program.
I am trying to compile this example program:
#include <ogdf/basic/Graph.h>
#include <ogdf/basic/graph_generators.h>
#include <ogdf/layered/DfsAcyclicSubgraph.h>
using namespace ogdf;
int main()
{
Graph G;
randomSimpleGraph(G, 10, 20);
DfsAcyclicSubgraph DAS;
DAS.callAndReverse(G);
G.writeGML("test.gml");
return 0;
}
using this command:
$g++ -pthread -I ./OGDF/ -L ./OGDF/_release/ -lOGDF test2.cpp
But I get the following error
/tmp/ccbpkfdt.o: In function `main':
test2.cpp:(.text+0x12): undefined reference to `ogdf::Graph::Graph()'
test2.cpp:(.text+0x2e): undefined reference to `ogdf::randomSimpleGraph(ogdf::Graph&, int, int)'
test2.cpp:(.text+0x4e): undefined reference to `ogdf::AcyclicSubgraphModule::callAndReverse(ogdf::Graph&)'
test2.cpp:(.text+0x62): undefined reference to `ogdf::Graph::writeGML(char const*) const'
test2.cpp:(.text+0x7f): undefined reference to `ogdf::Graph::~Graph()'
test2.cpp:(.text+0xa1): undefined reference to `ogdf::Graph::~Graph()'
/tmp/ccbpkfdt.o: In function `__static_initialization_and_destruction_0(int, int)':
test2.cpp:(.text+0xfb): undefined reference to `ogdf::Initialization::Initialization()'
test2.cpp:(.text+0x112): undefined reference to `ogdf::Initialization::~Initialization()'
/tmp/ccbpkfdt.o: In function `ogdf::DfsAcyclicSubgraph::DfsAcyclicSubgraph()':
test2.cpp:(.text._ZN4ogdf18DfsAcyclicSubgraphC2Ev[_ZN4ogdf18DfsAcyclicSubgraphC5Ev]+0x16): undefined reference to `vtable for ogdf::DfsAcyclicSubgraph'
/tmp/ccbpkfdt.o: In function `ogdf::DfsAcyclicSubgraph::~DfsAcyclicSubgraph()':
test2.cpp:(.text._ZN4ogdf18DfsAcyclicSubgraphD2Ev[_ZN4ogdf18DfsAcyclicSubgraphD5Ev]+0xb): undefined reference to `vtable for ogdf::DfsAcyclicSubgraph'
collect2: error: ld returned 1 exit status
I tried compiling hello world, with an include from OGDF, and I still got:
undefined reference to `ogdf::Initialization::Initialization()'
I think I am not linking properly or something?
You have to be very careful in which order you type stuff when linking with a library.
Try putting test2.cpp before -lOGDF instead, like this:
g++ -pthread -I ./OGDF/ -L ./OGDF/_release/ test2.cpp -lOGDF
You must build your program using the -DOGDF_DLL when using OGDF as a shared library.
See here: http://www.ogdf.net/doku.php/tech:defines
I can get other boost libraries to work in Eclipse C++ plugin, but have problem in boost thread. What's the problem?
#include <boost/thread/thread.hpp>
#include <iostream>
using namespace std;
void hello()
{
cout<<"hello world!"<<endl;
}
int main()
{
boost::thread thrd(&hello);
cout<<"Just a test!"<<endl;
return 0;
}
Error messages:
** Rebuild of configuration Debug for project Hello **
Internal Builder is used for build **
g++ -IC:\boost_1_47_0 -O0 -g3 -Wall -c -fmessage-length=0 -osrc\hello.o ..\src\hello.cpp
In file included from C:\boost_1_47_0/boost/thread/win32/thread_data.hpp:12,
from C:\boost_1_47_0/boost/thread/thread.hpp:15,
from ..\src\hello.cpp:1:
C:\boost_1_47_0/boost/thread/win32/thread_heap_alloc.hpp:59: warning: inline function 'void* boost::detail::allocate_raw_heap_memory(unsigned int)' declared as dllimport: attribute ignored
C:\boost_1_47_0/boost/thread/win32/thread_heap_alloc.hpp:69: warning: inline function 'void boost::detail::free_raw_heap_memory(void*)' declared as dllimport: attribute ignored
g++ -LC:\boost_1_47_0\stage\lib -oHello.exe src\hello.o -lboost_filesystem-mgw46-mt-d-1_47 -lboost_regex-mgw46-mt-1_47 -lboost_system-mgw46-mt-1_47 -lboost_thread-mgw46-mt-1_47 -lboost_date_time-mgw46-mt-1_47
src\hello.o: In function `main':
C:\Users\cmin\workspace\Hello\Debug/../src/hello.cpp:15: undefined reference to `_imp___ZN5boost6threadD1Ev'
C:\Users\cmin\workspace\Hello\Debug/../src/hello.cpp:15: undefined reference to `_imp___ZN5boost6threadD1Ev'
src\hello.o: In function `thread<void (*)()>':
C:/boost_1_47_0/boost/thread/detail/thread.hpp:204: undefined reference to `_imp___ZN5boost6thread12start_threadEv'
collect2: ld returned 1 exit status
Build error occurred, build is stopped
Time consumed: 1044 ms.
I am a leda-6.3 library user.
I used graphwin to manipulate and display graphs, but I found that references
to graphwin methods are undefined while compiling the code although they
are declared in the LEDA/incl/LEDA/graphics/graphwin.h
So I think it is a problem of object file.
#include <LEDA/graphics/graphwin.h>
#include <LEDA/graph/graph_alg.h>
using namespace leda;
int main()
{
GraphWin gw("LEDA Graph Editor");
node u=gw.new_node(point(100,100));
node v=gw.new_node(point(100,200));
gw.new_edge(u,v);
gw.display();
gw.get_window().read_mouse();
graph& G=gw.get_graph();
G.new_node();
gw.get_window().read_mouse();
gw.update_graph();
gw.get_window().read_mouse();
return 0;
}
compilation: g++ -I$LEDAROOT/incl -L$LEDAROOT gw.cpp -lleda -lX11 -lm -o gw
ERROR :
/tmp/ccVHyRbL.o: In function `main':
gw.cpp:(.text+0x1e): undefined reference to `leda::GraphWin::GraphWin(char const*)'
gw.cpp:(.text+0x58): undefined reference to `leda::GraphWin::new_node(leda::point const&)'
gw.cpp:(.text+0xc6): undefined reference to `leda::GraphWin::new_node(leda::point const&)'
gw.cpp:(.text+0x11c): undefined reference to `leda::GraphWin::new_edge(leda::node_struct*, leda::node_struct*)'
gw.cpp:(.text+0x128): undefined reference to `leda::GraphWin::display()'
gw.cpp:(.text+0x17e): undefined reference to `leda::GraphWin::update_graph()'
collect2: ld returned 1 exit status
Which edition of LEDA are you using?
Please consider that free edition of LEDA does not contain GraphWin.
So, it dos not contain GraphWin libraries, which results to getting such errors while compiling your program.