Socket programming issue with getaddrinfo()

[mcleano]

I can't work out how to get the getaddrinfo() function to work. I keep getting the error:

error C2664: 'getaddrinfo' : cannot convert parameter 1 from 'char' to 'PCSTR'
Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast

if(getaddrinfo(argv[1], port, &hints, &result) != 0) {
		std::cout << "Could not get address info!";
		WSACleanup();
		std::cin.get();
		return 1;
	}

The program compiles fine if this snippet isn't in it. Its where it says "port" that I seem to be getting the problem.

[R0mai]

PCSTR is a char *, and it seems you are passing an actual character (and not a pointer).

[mcleano]

That shouldn't be a problem though because of the declaration of port:

char *port = "27015";

Sorry, should have said that before.

[Gregor]

parameter 1. How is argv declared?

[Incubbus]

plz post your main functions head...

did u do it that way?

main(int argc, char **argv)

[mcleano]

No i did it like this:

#pragma comment(lib, "wsock32.lib")

#include <iostream>
#include <winsock2.h>
#include <ws2tcpip.h>

int main(int argc, char *argv)
{
	if(argc != 2) {
		std::cout << "Error! Usage: Client <hostname>";
		std::cin.get();
		return 1;
	}
	
	WSADATA wsaData;
	int iniResult = 0;
	char *port = "27015";

	iniResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
	if(iniResult != 0) {
		std::cout << "WSAStartup() failed to initialize!";
		std::cin.get();
		return 1;
	}
	
	struct addrinfo *result = NULL,
                *ptr = NULL,
                hints;

	SecureZeroMemory(&hints, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	if(getaddrinfo(argv[1], port, &hints, &result) != 0) {
		std::cout << "Could not get address info!";
		WSACleanup();
		std::cin.get();
		return 1;
	}

	
	std::cin.get();
	return 0;
}

[Incubbus]

as i wrote in my recent post: it hast to be char** argv not *argv , because it is an array of pointers to c-strings which u enter while starting the programm via the command line.

"client" --- "hostname" [arg3] [argx...[
/\ _______ /\ ________ /\
||________||_________||
argv[0] argv[1] argv[2] etc...

[mcleano]

that didn't wok though :S

I get the error:

1>Client.obj : error LNK2019: unresolved external symbol __imp__getaddrinfo@16 referenced in function _main
1 unresolved externals

[Incubbus]

guess u forgot to import the library/header...


wtf is wsock32.lib?

#pragma comment(lib, "Ws2_32") 

[mcleano]

Ok using your pragma comment let the code compile fine so thanks!

Btw, could you show me how to include this library without having to use pragma comment because I only used this because I'm new to using VC++ and don't know how to do it the other way - this was just a way I found whilst searching for a solution.