以下内容为UDP网络通信中服务器的简单示例代码：
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
int main(int argc, char* argv[])
{
int err, sfd;
//1)把IP地址，IP协议族封装成套接字socket
sfd = socket(AF_INET, SOCK_DGRAM, 0);
if(sfd < 0)
{
printf("Failed to create socket\n");
return -1;
}
printf("The socket was created successfully\n");
//2)编写服务器信息结构体
struct sockaddr_in saddr;
memset(&saddr, 0, sizeof(saddr));
saddr.sin_family = AF_INET;//地址协议族
saddr.sin_port = htons(atoi(argv[2]));//端口号
saddr.sin_addr.s_addr = inet_addr(argv[1]); //把点分十进制IP转换成4字节
//3)把套接字绑定成监听套接字bind
err = bind(sfd, (struct sockaddr *)&saddr, sizeof(saddr));
if(err < 0)
{
printf("Binding failure\n");
return -1;
}
printf("Binding success\n");
//4)通过数据包发送/接收函数进行网络通信sendto/recvfrom
char buf[65];
while(1)
{
memset(buf, 0, sizeof(buf));
recvfrom(sfd, buf, sizeof(buf)-1, 0, NULL, NULL);
printf("buf = %s", buf);
}
//5)关闭套接字close
close(sfd);
return 0;
}
以上内容主要使用了socket、bind、recvfrom等函数实现在服务器中实时监测从客户端发来的信息并显示
函数相关使用说明在上一个帖子UDP网络通信中