代码实现：分为udpSer.c(服务器端)和udpCli.c(客户端)

//udpSer.c
#include <myhead.h>

#define SER_PORT 9999
#define SER_IP "192.168.83.128"

int main(int argc, 	const char *argv[])
{
	//1、创建用于通信的服务器套接字文件描述符
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd == -1)
	{
		perror("socket error");
		return -1;
	}
	printf("sfd = %d\n", sfd);      //3

	//端口号快速重用
	int reuse = 1;
	if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse)) == -1)
	{
		perror("setsockopt error");
		return -1;
	}
	printf("端口号快速重用成功\n");

	//2、绑定ip地址和端口号
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(SER_PORT);
	sin.sin_addr.s_addr = inet_addr(SER_IP);

	//2.2绑定工作
	if(bind(sfd,(struct sockaddr *)&sin,sizeof(sin)) == -1)
	{
		perror("bind error");
		return -1;
	}
	printf("bind success\n");
	

	//3、数据收发
	char buf[128] = "";
	struct sockaddr_in cin;       //接受对端地址信息
	socklen_t addrlen = sizeof(cin);

	while(1)
	{
		//清空容器
		bzero(buf,sizeof(buf));

		//从套接字中读取数据
		recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr *)&cin,&addrlen);

		printf("收到消息为:%s\n",buf);

		strcat(buf,"*+*");
		if((sendto(sfd,buf,strlen(buf),0,(struct sockaddr *)&cin,sizeof(cin))) == -1)
		{
			perror("发送 error");
			return -1;
		}
	}

	//4、关闭文件描述符
	close(sfd);
	return 0;
}

//udpCli.c
#include <myhead.h>

#define SER_PORT 9999
#define SER_IP "192.168.83.128"
#define CLI_PORT 3333
#define CLI_IP "192.168.83.128"

int main(int argc, 	const char *argv[])
{
	//1、创建用于通信的服务器套接字文件描述符
	int cfd = socket(AF_INET,SOCK_DGRAM,0);
	if(cfd == -1)
	{
		perror("socket error");
		return -1;
	}
	printf("cfd = %d\n", cfd);      //3

	//将端口号快速重用
	int reuse = 1;
	if(setsockopt(cfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse))==-1)
	{
		perror("setsockopt error");
		return -1;
	}
	printf("端口号快速重用成功\n");

	//2、绑定ip地址和端口号
	struct sockaddr_in cin;
	cin.sin_family = AF_INET;
	cin.sin_port = htons(CLI_PORT);
	cin.sin_addr.s_addr = inet_addr(CLI_IP);

	//2.2绑定工作
	if(bind(cfd,(struct sockaddr *)&cin,sizeof(cin)) == -1)
	{
		perror("bind error");
		return -1;
	}
	printf("bind success\n");


	//3、数据收发
	char buf[128] = "";
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(SER_PORT);
	sin.sin_addr.s_addr = inet_addr(SER_IP);

	while(1)
	{
		printf("请输入>>>");
		fgets(buf,sizeof(buf),stdin);
		buf[strlen(buf) - 1] = 0;


		//将数据发送给服务器
		sendto(cfd,buf,strlen(buf),0,(struct sockaddr*)&sin,sizeof(sin));
		printf("发送成功\n");

		bzero(buf,sizeof(buf));

		recvfrom(cfd,buf,sizeof(buf),0,NULL,NULL);
		printf("收到服务器消息为:%s\n",buf);

	}

	//4、关闭文件描述符
	close(cfd);
	return 0;
}

输出结果如下：成功从客户端发送信息到服务器中