c - 套接字编程-setsockopt : Protocol not available?

Question

我正在用 C 语言进行一些基本的套接字编程，并且在我尝试运行代码的每台计算机上都遇到了此错误。代码编译得很好，但是当我尝试运行它时，我收到错误setsockopt:协议(protocol)不可用。这似乎不是一个很常见的错误，但我尝试运行它的每台计算机上都会遇到这个错误。所有计算机都是 MacOS。

#include <unistd.h> 
#include <stdio.h> 
#include <sys/socket.h> 
#include <stdlib.h> 
#include <netinet/in.h> 
#include <string.h> 
#define PORT 8080 
int main(int argc, char const *argv[]) 
{ 
    int server_fd, new_socket, valread; 
    struct sockaddr_in address; 
    int opt = 1; 
    int addrlen = sizeof(address); 
    char buffer[1024] = {0}; 
    char *hello = "Hello from server"; 

    // Creating socket file descriptor 
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) 
    { 
        perror("socket failed"); 
        exit(EXIT_FAILURE); 
    } 

    // Forcefully attaching socket to the port 8080 
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, 
                                                  &opt, sizeof(opt))) 
    { 
        perror("setsockopt"); 
        exit(EXIT_FAILURE); 
    } 
    address.sin_family = AF_INET; 
    address.sin_addr.s_addr = INADDR_ANY; 
    address.sin_port = htons( PORT ); 

    // Forcefully attaching socket to the port 8080 
    if (bind(server_fd, (struct sockaddr *)&address,  
                                 sizeof(address))<0) 
    { 
        perror("bind failed"); 
        exit(EXIT_FAILURE); 
    } 
    if (listen(server_fd, 3) < 0) 
    { 
        perror("listen"); 
        exit(EXIT_FAILURE); 
    } 
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address,  
                       (socklen_t*)&addrlen))<0) 
    { 
        perror("accept"); 
        exit(EXIT_FAILURE); 
    } 
    valread = read( new_socket , buffer, 1024); 
    printf("%s\n",buffer ); 
    send(new_socket , hello , strlen(hello) , 0 ); 
    printf("Hello message sent\n"); 
    return 0; 
} 

有人告诉我，我需要包含setsockopt()方法，以便重新启动的进程可以连接到该地址，而不会因为tcp连接关闭后的等待时间而被阻塞。有人知道如何修复这个错误吗？

Answer 1

我也遇到了类似的问题，只需替换这段代码即可

// Forcefully attaching socket to the port 8080 
if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt)))

有了这个

// Forcefully attaching socket to the port 8080 
if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR , &opt, sizeof(opt)))

这对我来说很有效(在 macOS 上)。