linux高级编程,tcp服务器select模式,编程
时间: 2024-03-07 22:46:48 浏览: 13
以下是一个简单的使用select模式实现TCP服务器的代码示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/select.h>
#define MAX_CLIENTS 10
#define BUFFER_SIZE 1024
int main(int argc, char *argv[])
{
int listen_fd, client_fd, max_fd;
int client_fds[MAX_CLIENTS];
int i, ret, nready;
struct sockaddr_in server_addr, client_addr;
socklen_t client_len;
char buffer[BUFFER_SIZE];
fd_set read_fds, all_fds;
// 创建监听socket
listen_fd = socket(AF_INET, SOCK_STREAM, 0);
if (listen_fd < 0) {
perror("socket");
exit(EXIT_FAILURE);
}
// 绑定监听socket到指定端口
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
server_addr.sin_port = htons(8888);
if (bind(listen_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("bind");
exit(EXIT_FAILURE);
}
// 监听端口,设置最大连接队列
if (listen(listen_fd, MAX_CLIENTS) < 0) {
perror("listen");
exit(EXIT_FAILURE);
}
// 初始化client_fds数组和all_fds集合
for (i = 0; i < MAX_CLIENTS; i++) {
client_fds[i] = -1;
}
FD_ZERO(&all_fds);
FD_SET(listen_fd, &all_fds);
max_fd = listen_fd;
// 进入主循环,等待客户端连接请求和数据传输请求
while (1) {
read_fds = all_fds;
nready = select(max_fd + 1, &read_fds, NULL, NULL, NULL);
if (nready < 0) {
perror("select");
exit(EXIT_FAILURE);
}
// 处理新的客户端连接请求
if (FD_ISSET(listen_fd, &read_fds)) {
client_len = sizeof(client_addr);
client_fd = accept(listen_fd, (struct sockaddr *)&client_addr, &client_len);
if (client_fd < 0) {
perror("accept");
continue;
}
// 将新的连接socket加入到client_fds数组和all_fds集合中
for (i = 0; i < MAX_CLIENTS; i++) {
if (client_fds[i] < 0) {
client_fds[i] = client_fd;
break;
}
}
if (i == MAX_CLIENTS) {
fprintf(stderr, "too many clients\n");
close(client_fd);
continue;
}
FD_SET(client_fd, &all_fds);
if (client_fd > max_fd) {
max_fd = client_fd;
}
printf("new client connected: %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
}
// 处理已连接客户端的数据传输请求
for (i = 0; i < MAX_CLIENTS; i++) {
if (client_fds[i] < 0) {
continue;
}
if (FD_ISSET(client_fds[i], &read_fds)) {
ret = recv(client_fds[i], buffer, BUFFER_SIZE, 0);
if (ret < 0) {
perror("recv");
close(client_fds[i]);
FD_CLR(client_fds[i], &all_fds);
client_fds[i] = -1;
continue;
}
if (ret == 0) {
printf("client disconnected: %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
close(client_fds[i]);
FD_CLR(client_fds[i], &all_fds);
client_fds[i] = -1;
continue;
}
// 处理客户端发送的数据
buffer[ret] = '\0';
printf("received data from client: %s", buffer);
}
}
}
return 0;
}
```
注意,上述代码只是一个简单的示例,实际使用中需要根据具体业务需求进行修改和完善。同时,为了简化代码,上述示例没有进行错误处理和异常情况的处理,实际使用中需要进行充分的异常情况处理。