Socket connect error c socket - c++

Question

I made a simple client program who connect to server via port 80;
int v=connect(mysocket,(struct sockaddr *)&server,sizeof(server));
if(v==SOCKET_ERROR){
cout<<"error connecting to server";
}
if (v==0) cout<<"connected"<<endl;
its says connect return 0 if success.
but i get the error;
can you please tell me when i must use htonl or htons i used only server.sin_port=htons(80);
should i use server.sin_addr.s_addr=inet_addr("someip_ignorethis"); or i must use
server.sin_addr.s_addr=htonl(inet_addr("someip_ignorethis"));
what is the problem WHY AND WHEN i need to use host to network conversation,how does it make my program portable???.
what socket i must use? socket version 2,2?
THNAKS FOR THE HELP!
I get 10038 ERROR HELP FIX MY CODE pastebin.com/4pdqsGqW

Answer 1

If you had bothered to use your debugger and debug the code yourself, you would have found that your mySocket variable is always 0, because you are not initializing it correctly.
This line:
if (mysocket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP)==INVALID_SOCKET){
Is effectively the same as this:
if (mysocket=(socket(AF_INET,SOCK_STREAM,IPPROTO_TCP)==INVALID_SOCKET)){
If socket() succeeds, ==INVALID_SOCKET evaluates as false, so 0 is assigned to mysocket. Read up on Operator Precedence. The == operator has a higher precedence than the = operator.
To fix it, change that line to this instead:
if ((mysocket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==INVALID_SOCKET){
Or better, get out of the habit of assigning and comparing a variable in the same statement:
mysocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
if (mysocket==INVALID_SOCKET){
Also, if you had bothered to pay attention to your compiler's output messages, you would have seen that your "CONNECTED!" message is code that is never reached, because it is inside the curly braces for when connect() fails, but there is a return before you print the message.
Try this code instead:
#include <winsock2.h>
#include <iostream.h>
#include <windows.h>
//#define portnumber 80
using namespace std;
//Winsock Library
int main(int argc, char* argv[])
{
WSADATA ws = {0};
int v = WSAStartup(MAKEWORD(2,2), &ws);
if (v != 0)
{
cout << "error initialising winsock: " << v << endl;
getchar();
return 1;
}
cout << "winsock started" << endl;
SOCKET mysocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (mysocket == INVALID_SOCKET)
{
cout << "error creating socket: " << WSAGetLastError() << endl;
getchar();
return 1;
}
cout << "socket created" << endl;
struct sockaddr_in server = {0};
server.sin_family = AF_INET;
server.sin_addr.s_addr = inet_addr("84.95.234.174");
//cout << inet_ntoa(server.sin_addr) << endl;
server.sin_port = htons(80);
if (connect(mysocket, (struct sockaddr *)&server, sizeof(server)) == SOCKET_ERROR)
{
cout << "error connecting to server: " << WSAGetLastError() << endl;
getchar();
return 1;
}
cout << "CONNECTED!" << endl;
getchar();
closesocket(mysocket);
return 0;
}

Answer 2

10038 is WSAENOTSOCK. Clearly the value of socket is invalid.
You should have found all that out for yourself before you posted, and looked up what the error meant as well.

Answer 3

Personally, I use this and it never fails me..
struct addrinfo *it = nullptr, *result = nullptr;
getaddrinfo(Address.c_str(), nullptr, nullptr, &result);
for (it = result; it != nullptr; it = it->ai_next)
{
sockaddr_ipv4 = reinterpret_cast<sockaddr_in*>(it->ai_addr);
Address = inet_ntoa(sockaddr_ipv4->sin_addr);
if (Address != "0.0.0.0") break;
}
freeaddrinfo(result);
And I use:
struct sockaddr_in SockAddr;
memset(&SockAddr, 0, sizeof(SockAddr));
SockAddr.sin_port = htons(Port);
SockAddr.sin_family = AF_INET;
SockAddr.sin_addr.s_addr = Address == "INADDR_ANY" ? htonl(INADDR_ANY) : inet_addr(Address.c_str());
if (connect(socket, reinterpret_cast<SOCKADDR*>(&SockAddr), sizeof(SockAddr)) == SOCKET_ERROR)
{
//print error.. clean up..
}
What it does is it checks the address. If it is INADDR_ANY, then it will use htonl. If not, it uses inet_addr to convert the address into an IP. Htonl on the other hand just converts the address into network byte order.