这是最简单的一种服务器模型,简单到实际开发中基本就不怎么能见到,其工作模式就是在一个死循环里不停的accept,如果有客户端接入,就进入一个子循环处理客户端的请求,直到客户端断开连接为止,然后再阻塞在accept,等待下一个客户端的接入,下面直接上代码
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <sys/types.h> /* See NOTES */ #include <sys/socket.h> #include <netinet/in.h> #include <netinet/ip.h> /* superset of previous */ #include <arpa/inet.h> #define LISTEN_BACKLOG 50 #define handle_error(msg) \ do { perror(msg); exit(EXIT_FAILURE); } while (0) int main(int argc, char ** argv) { int i = 0; int sockfd = 0; int acceptfd = 0; ssize_t readret = 0; socklen_t client_addr_len = 0; struct sockaddr_in server_addr, client_addr; char client_ip[16] = { 0 }; char read_buff[256] = { 0 }; char write_buff[256] = { 0 }; memset(&server_addr, 0, sizeof(server_addr)); memset(&client_addr, 0, sizeof(client_addr)); if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) handle_error("socket"); server_addr.sin_family = AF_INET; server_addr.sin_port = htons(9527); server_addr.sin_addr.s_addr = htonl(INADDR_ANY); if(bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) { close(sockfd); handle_error("bind"); } if(listen(sockfd, LISTEN_BACKLOG) < 0) { close(sockfd); handle_error("listen"); } while(1) { client_addr_len = sizeof(client_addr); if((acceptfd = accept(sockfd, (struct sockaddr *)&client_addr, &client_addr_len)) < 0) { close(sockfd); handle_error("accept"); } memset(client_ip, 0, sizeof(client_ip)); inet_ntop(AF_INET,&client_addr.sin_addr,client_ip,sizeof(client_ip)); printf("client:%s:%d\n",client_ip,ntohs(client_addr.sin_port)); i = 0; while (1) { memset(read_buff, 0, sizeof(read_buff)); readret = read(acceptfd, read_buff, sizeof(read_buff)); if (readret == 0) break; printf("%s\n", read_buff); memset(write_buff, 0, sizeof(write_buff)); sprintf(write_buff, "This is server send message:%d", i++); write(acceptfd, write_buff, sizeof(write_buff)); } printf("\n"); close(acceptfd); sleep(1); } close(sockfd); return 0; }这种模式只能同时处理一个客户端的请求,其他客户端需要排队等待,很显然效率是非常低的。虽然这种模式简单,但却是后面其他所有模式服务端的基础。