c - Linux C 如何为 http 响应 block 动态分配内存？

Question

我是 C 的新手，我正在尝试将 BUFSIZE 的 http 响应 block “附加”到字符串 total_response 中，然后返回它，我该怎么做呢？

char *
http_request(char * postdata, char * method, char * host, char * page,
             int port, char * useragent)
{
    struct sockaddr_in * remote;
    int sock;
    int tmpres;
    char * ip, * get;

    sock = create_tcp_socket();
    ip = get_ip(host);
    remote = (struct sockaddr_in * ) malloc(sizeof(struct sockaddr_in * ));
    remote -> sin_family = AF_INET;
    tmpres = inet_pton(AF_INET, ip, (void *)(&(remote -> sin_addr.s_addr)));
    if (tmpres < 0)
    {
//error
        return 0;
    }
    else if (tmpres == 0)
    {
//error
        return 0;
    }
    remote -> sin_port = htons(port);

    if (connect(sock, (struct sockaddr * ) remote, sizeof(struct sockaddr)) < 0)
    {
//error
        return 0;
    }
    get = build_get_query(postdata, method, HOST, PAGE, USERAGENT);
    //fprintf(stderr, "%s", get);  //response

    // Send the query to the server
    int sent = 0;
    while (sent < strlen(get))
    {
        tmpres = send(sock, get + sent, strlen(get) - sent, 0);
        if (tmpres == -1)
        {
//error
            return 0;
        }
        sent += tmpres;
    }
    // now it is time to receive the page
    char buf[BUFSIZ + 1];
    memset(buf, 0, sizeof(buf));
    int bytes;
    do
    {
        memset(buf, 0, sizeof(buf));
        bytes = recv(sock, buf, 1024, 0);
        printf("%s", buf); //handle response chunks
        if (bytes < 0)
            perror("ERROR reading response from socket");
        if (bytes == 0)
            break;
    }
    while (1);
    free(get);
    free(remote);
    free(ip);
    close(sock);
    return "CANT RETURN LOCAL VARIABLE BUF?";
}

非常感谢任何帮助，谢谢!

Answer 1

您可以首先使用malloc 分配 block ，如果发现 block 不够大，可以使用realloc 来扩大它。然后您可以返回 指向该 block 的指针(不要忘记在末尾放置一个终止零字节)。调用方可以在 block 用完后释放 block 。