socket problem

Hi.

I was trying to make this teste server, but i have a problem. The socket can't be opened. The code compiled well, but when i launch the .exe file, i get the error "Can't creat socket." and I just don't understand why. Here his an extract of the code:

Code:

#define _WINSOCKAPI_
#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <Winsock2.h>
#include "useful.h"
//requires Ws2_32.lib

int main(int argc, char** argv) {

	SOCKET sockfd;
	int rm;
	char message[256];
	struct sockaddr_in serv_addr;
	//hostent* localHost;
	//char* localIP;

	if(argc != 3)
		error_dump("Invalid parameters.\n");
		
	if((sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
		error_dump("Can't creat socket.\n");

Another problem was that hostent* was not recognized besides including Winsock2.h and compiling with Ws2_32.lib.

Can someone help me?

Thanks a lot.

My best regards.

PS: I've windows XP sp2

Under Windows, you must make a call to WSAStartup() before using any socket functions. (And you should also call WSACleanup() when finished.)

Code:

	struct hostent*		hostEnt;
	HOSTENT*		hostEnt;

Gee... so complicated. I've found an example on msdn. Linux is so much easier. Isn't there a smaller way to do that?

Here is that huge example:
http://msdn.microsoft.com/library/de...cketserver.asp

Thanks a lot.

Getting started with winsock: http://msdn.microsoft.com/library/de...th_winsock.asp

Client: http://msdn.microsoft.com/library/de...lient_code.asp
Server: http://msdn.microsoft.com/library/de...erver_code.asp

Thanks a lot

Hi. I've had another problem. After spending lots of hours searching on MSDN and other sites, i can't find the right solution. When i use gethostbyname it returns the wrong IP address (like de LAN ip when I want the inet one). I read about that problem, and the solution seems to to be using GetAdaptersAddresses or GetAdaptersInfo. GetAdaptersAddresses seems to be good but i cant get the IP from it, just other info. Can anybody help? Thanks!

before making a call to socket() you must call WSAStartup, here's a piece of code from a class i made that estamblishes a connection:

Code:

	bool make_connection()
	{
	  WSADATA wsaData;
	  struct hostent *h;
	  
      if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
	  {
	    error_log = "WSAStartup()\n";
	    return false;
	  }

	  if ((h = gethostbyname(host.c_str())) == 0)
	  {
		error_log = "gethostbyname()\n";
		return false;
	  }

	  memset(&address, 0, sizeof address);
	  address.sin_family = AF_INET;
	  address.sin_port = htons(port);
	  memcpy(&address.sin_addr.s_addr, h->h_addr_list[0], h->h_length);

	  if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	  {
		error_log = "socket()\n";
		return false;
	  }

	  if (connect(sock, (struct sockaddr *)&address, sizeof address) == -1)
	  {
	    closesocket(sock);
        error_log = "connect";
     	return false;
	  }

	  is_connected = true;
	  return true;
	}

Wow, that looks more simple. What's that "host" anyway?

Code:

host.c_str()

thanks

host is a just a private std::string in my class but you can use an average char * instead of host.c_str(), the class is in c++ so you might want to change it a bit. address var is of type struct sockaddr_in and is also a member of the class.