Question

我正在尝试向网站的根文档发送HEAD请求。这是我的代码：

main(int argc, char *argv[])
{
    int csd;
    struct sockaddr_in server;
    struct hostent *server_host;
    int server_len;
    int string_size;
    short server_port;
    char req_buffer[BUF_LEN];
    char temp_buffer[BUF_LEN];
    char receiveBuffer[BUF_LEN];
    char resource_buffer[BUF_LEN];
    int t;

    if(argc!=2)
    {
        fprintf(stderr,"Usage: %s website \n",argv[0]);
        exit(EXIT_FAILURE);
    }

    server_host=gethostbyname(argv[1]); //resolve hostname
    if (server_host == NULL)
    {
        herror("While calling gethostbyname()");
        exit(EXIT_FAILURE);
    }

    csd=socket(PF_INET, SOCK_STREAM, 0); //create socket
    if(csd<0)
    {
        perror("While calling socket()");
        exit(EXIT_FAILURE);
    }

    server.sin_family=AF_INET;
    memcpy(&server.sin_addr, server_host->h_addr_list[0], server_host->h_length);
    server.sin_port = htons(80);
    server_len=sizeof(server);
    t = connect(csd, (struct sockaddr *) &server, server_len);
    if (t<0)
    {
        perror("while connecting()");
        exit(EXIT_FAILURE);
    }
    else
    {
        printf("connected to server\n\n");
    }

    printf("input resource, with format'/(resource name)'\n"); //request for resource (for example /index.html)
    scanf("%s", temp_buffer);
    printf("retreiving HEAD...\n\n");

    sprintf(temp_buffer, "HEAD %s HTTP/1.0\r\n", resource_buffer);
    strcpy(req_buffer, temp_buffer);
    sprintf(temp_buffer, "HOST: %s\r\n", server_host);
    strcat(req_buffer, temp_buffer);

    sprintf(temp_buffer, "\r\n");
    strcat(req_buffer, temp_buffer);

    write(csd, req_buffer, strlen(req_buffer));

    read(csd, receiveBuffer, BUF_LEN);

    printf(receiveBuffer);
}

到目前为止，我还没有成功，我只是得到了不好的要求。我使用网站测试：man7.org/linux/man-pages/index.html和man7.org/mtk/index.html

Answer 1

首先，您使用的是HTTP 1.0上不存在的host标头，您需要使用1.1。还要添加connection: close以确保不使用keepalive。

主要问题很可能是您在主机标头中使用server_host。它不是字符串，它是一个结构体，因此它会将垃圾输出到您的请求中。

简单的调试会话或只输出您发出的请求会显示此错误。

C - 如何向网站发送正确的HEAD请求？

1 个答案: