#include <sys/types.h>
#include <sys/socket.h>
int socket(int domain, int type, int protocol);
int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
int listen(int sockfd, int backlog);
int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);
int connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
socket 用于创建一个套接字,它是通信的端点
AF_INET
(IPv4)和 AF_INET6
(IPv6).SOCK_STREAM
(流套接字,用于TCP)和 SOCK_DGRAM
(数据报套接字,用于UDP).bind 用于绑定一个地址到套接字
listen 用于监听套接字,使其能够接受连接请求
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#define PORT 8080
#define MAX_PENDING_CONNECTIONS 5
int main() {
int server_socket, client_socket;
struct sockaddr_in server_addr, client_addr;
socklen_t client_addr_len = sizeof(client_addr);
// 创建套接字
server_socket = socket(AF_INET, SOCK_STREAM, 0);
if (server_socket == -1) {
perror("Socket creation failed");
exit(EXIT_FAILURE);
}
// 设置服务器地址结构
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
server_addr.sin_port = htons(PORT);
// 绑定套接字
if (bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
perror("Bind failed");
exit(EXIT_FAILURE);
}
// 监听套接字
if (listen(server_socket, MAX_PENDING_CONNECTIONS) == -1) {
perror("Listen failed");
exit(EXIT_FAILURE);
}
printf("Server listening on port %d...\n", PORT);
// 接受连接并处理
while (1) {
// 等待客户端连接
client_socket = accept(server_socket, (struct sockaddr *)&client_addr, &client_addr_len);
if (client_socket == -1) {
perror("Accept failed");
exit(EXIT_FAILURE);
}
// 处理连接,这里简单打印客户端的信息
printf("Connection accepted from %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
// 在这里可以进行进一步的通信处理,读取/写入数据等
// 关闭客户端套接字
close(client_socket);
}
// 关闭服务器套接字
close(server_socket);
return 0;
}
#include <arpa/inet.h>
uint32_t htonl(uint32_t hostlong);
uint16_t htons(uint16_t hostshort);
uint32_t ntohl(uint32_t netlong);
uint16_t ntohs(uint16_t netshort);