access violation when connecting to server

Hey folks! :D

Here's the compilable code. The line in red is what causes the access violation.

Code:

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#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>

#define STORAGE_LEN 1000
#define DEFAULT_PORT "80"

char storage[STORAGE_LEN];
SOCKET ConnectSocket = INVALID_SOCKET;

void write_to_file(char *storage)
{
        FILE *p_openfile = fopen("c:\\programs\\networking\\webpagecontent.txt" , "a+");
        fprintf(p_openfile, "%s\n", storage);
        fclose(p_openfile);
}

int main(int argc, char **argv)
{
        WSADATA wsaData;
        int iResult;
        struct addrinfo *result = NULL,
                                *ptr = NULL,
                                hints;

        // Validate parameters
        if(argc !=2) {
                printf("usage: %s server-name\n", argv[0]);
                return 1;
        }

        // Initialize Winsock
        iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
        if(iResult != 0) {
                printf("WSAStartup failed: %d\n", iResult);
                return 1;
        }

        sprintf(storage, "WSAStartup = %d\n", iResult);
        write_to_file(storage);

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

        // Resolve the server address and port
        iResult = getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result);
        if(iResult != 0) {
                printf("getaddrinfo failed: %d\n", iResult);
                WSACleanup();
                return 1;
        }

        sprintf(storage, "getaddrinfo = %d\n", iResult);
        write_to_file(storage);

        // Attempt to connect to an address until one succeeds
        for(ptr = result; ptr != NULL; ptr = ptr->ai_next) {
               
                // Create a socket for connecting to the server
                ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol);
                if(ConnectSocket == INVALID_SOCKET) {
                        printf("Error at socket(): %ld\n", WSAGetLastError());
                        freeaddrinfo(result);
                        WSACleanup();
                        return 1;
                }
        }

        sprintf(storage, "socket = %d\n", ConnectSocket);
        write_to_file(storage);

        // Connect to server
        iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
        if(iResult == SOCKET_ERROR) {
                closesocket(ConnectSocket);
                ConnectSocket = INVALID_SOCKET;
        }

        freeaddrinfo(result);

        if(ConnectSocket == INVALID_SOCKET) {
                printf("Unable to connect to the server!\n");
                return 1;
        }

        return 0;
}

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I am still a bit too newbie to know what is the exact problem. Is it because ptr is NULL? Am I supposed to create another struct addrinfo object, and assign ptr to it?

If I was to write

Code:

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ptr = result;

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before the line in red, a SOCKET ERROR is the result.

Thanks in advance. :D

Oh, found the problem, I should have closed the for() loop in blue after the connection was made to the server, because ptr is still needed. :D