undefined reference to `__imp_WSACleanup' - c++

Question

This is my first program with winsock. As you can see, I've #include <winsock2.h> and linked ws2_32.dll, but the code still doesn't compile:
#include<winsock2.h>
#pragma comment(lib, "ws2_32")
class CInitSock{
public:
CInitSock(BYTE minorVer=2,BYTE majorVer=2){
//initialize WS2_32.dll
WSADATA wsaData;
WORD sockVersion = MAKEWORD(minorVer,majorVer);
if(::WSAStartup(sockVersion,&wsaData)!=0){
exit(0);
}
}
//release winSock libary
~CInitSock(){
::WSACleanup();
}
};
#include "CInitSock.h"
#include<stdio.h>
CInitSock initSock;
int main(void){
char szHost[256];
::gethostname(szHost,256);
hostent *phost = ::gethostbyname(szHost);
in_addr addr;
for(int i = 0;;i++){
char *p = phost->h_addr_list[i];
if(p==NULL){
break;
}
memcpy(&addr.S_un.S_addr,p,phost->h_length);
char *szIp = ::inet_ntoa(addr);
printf("%s \n",szIp);
}
}
This is the error:
mingw32-make.exe -f "D:\project\c_program\Makefile.win" all
g++.exe GetAllIPs.o -o win_socket.exe -L"D:/tools/develepment/Dev-Cpp/MinGW64/x86_64- w64-mingw32/lib" -L"D:/tools/develepment/Dev-Cpp/MinGW64/lib32" -static-libgcc -mwindows -g3
GetAllIPs.o: In function `main':
D:\project\c_program/GetAllIPs.cpp:6: undefined reference to `__imp_gethostname'
D:\project\c_program/GetAllIPs.cpp:7: undefined reference to `__imp_gethostbyname'
D:\project\c_program/GetAllIPs.cpp:15: undefined reference to `__imp_inet_ntoa'
GetAllIPs.o: In function `CInitSock::CInitSock(unsigned char, unsigned char)':
D:\project\c_program/CInitSock.h:10: undefined reference to `__imp_WSAStartup'
GetAllIPs.o: In function `CInitSock::~CInitSock()':
D:\project\c_program/CInitSock.h:16: undefined reference to `__imp_WSACleanup'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe: *** [win_socket.exe] Error 1
Now I'm totally confused...

Answer 1

The pragma you use only works for the Visual C++ Compiler and will be ignored by the gcc
#pragma comment(lib, "ws2_32")
you have to add the ws2_32.lib it manually in the makefile.
like:
-L"ws2_32"
(I guess it was without the ".lib" at the end)
at the end of the g++ line. You have of course add the full path which I have not by hand at the moment.

Answer 2

I met the same problem with you. I solved it by adding a command -lwsock32.
you can add the command according follow steps:
tools
compiler options
choose general
click add the following commands when calling the compilers
then you can add the above command -lwsock32.

Answer 3

add
-lwsock32
to your command-line instead of #pragma when compiling with MinGW
g++ src/main.cpp -o release/myApp.exe -lwsock32

Answer 4

In DevC++, navigate to Project >> Project Options (or via usually ctrl+h); then in the "Parameters" tab there is a button "Add Library or Object" and then add libws2_32.a.

Answer 5

For codeblocks under wnidows : go to
Project -> Build Options -> Linker settings (make sure the project is selected on the left, not a build target) and add (type in) in the left list the library "ws2_32"