需求：
	软件划分为用户客户端和主播服务端两个软件client.c和server.c 

用户客户端负责：
    1.接收用户的昵称
    2.接收用户输入的信息，能够将信息发送给服务端
    3.接收服务端回复的数据信息,并完成显示

主播服务端负责：
    1.对所有加入直播间的用户的IP地址和端口实现管理（加入、退出）
    2.当有新的客户端加入时,能够向所有客户端提示:"欢迎 XXX 用户进入直播间"
    3.当有客户端退出时,能够向所有客户端提示:"XXX 离开直播间"
    4.能够实现客户端聊天内容的转发,当某个客户端发送聊天信息时,能够将该信息转给除了该用户之外聊天室内所有其余客户端用户

head.h文件

#ifndef __HEAD_H__
#define __HEAD_H__

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <time.h>
#include <pwd.h>
#include <grp.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include <netinet/in.h>

struct address
{
	int mark;
	struct sockaddr_in addr;
};

struct msgbuf{
	int type;
	char name[32];
	char text[512];
};

#define MSG_TYPE_START		100
#define MSG_TYPE_END		200
#define MSG_TYPE_CHAT		300
#define RECV_ADDR			"192.168.1.152"
#define RECV_PORT			50000

#endif

client.c

#include "head.h"

char name[32] = {0};
int sockfd = 0;
struct sockaddr_in recvaddr;
pthread_t tid_send;		//发线程
pthread_t tid_recv;		//收线程

void *sendfun(void *arg)
{
	struct msgbuf sendmsg;	
	ssize_t nsize = 0;

	while (1)
	{
		memset(&sendmsg, 0, sizeof(sendmsg));
		sendmsg.type = MSG_TYPE_CHAT;
		sprintf(sendmsg.name, "%s", name);
		gets(sendmsg.text);
		
		if (!strcmp(sendmsg.text, ".quit"))
		{
			sendmsg.type = MSG_TYPE_END;
		}

		nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
		if (-1 == nsize)
		{
			perror("fail to sendto");
			return NULL;
		}

		if (sendmsg.type == MSG_TYPE_END)
		{
			break;
		}
	}

	pthread_cancel(tid_recv);
	
	return NULL;
}

void *recvfun(void *arg)
{
	struct msgbuf recvmsg;
	ssize_t nsize = 0;

	while (1)
	{
		memset(&recvmsg, 0, sizeof(recvmsg));
		nsize = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, NULL, NULL);
		if (-1 == nsize)
		{
			perror("fail to recvfrom");
			return NULL;
		}

		if (recvmsg.type == MSG_TYPE_CHAT)
		{
			printf("%s(%s:%d)>%s\n", recvmsg.name, RECV_ADDR, RECV_PORT, recvmsg.text);
		}
		else if (recvmsg.type == MSG_TYPE_END)
		{
			break;
		}
	}
	
	pthread_cancel(tid_send);

	return NULL;
}

int main(void)
{
	struct msgbuf sendmsg;
	ssize_t nsize = 0;

	recvaddr.sin_family = AF_INET;
	recvaddr.sin_port = htons(RECV_PORT);
	recvaddr.sin_addr.s_addr = inet_addr(RECV_ADDR);

	printf("请输入您的昵称:\n");
	gets(name);

	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (-1 == sockfd)
	{
		perror("fail to socket");
		return -1;
	}
	
	memset(&sendmsg, 0, sizeof(sendmsg));
	sendmsg.type = MSG_TYPE_START;
	sprintf(sendmsg.name, "%s", name);
	nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
	if (-1 == nsize)
	{
		perror("fail to sendto");
		return -1;
	}

	pthread_create(&tid_send, NULL, sendfun, NULL);
	pthread_create(&tid_recv, NULL, recvfun, NULL);

	pthread_join(tid_send, NULL);
	pthread_join(tid_recv, NULL);

	close(sockfd);

	return 0;
}

server.c

#include "head.h"

struct address ClientIpList[100];

int AddClientIp(struct sockaddr_in TmpAddr)
{
	int i = 0;

	for(i = 0;i < 100;++i)
	{
		if(ClientIpList[i].mark == 0)
		{
			ClientIpList[i].addr = TmpAddr;
			ClientIpList[i].mark = 1;
			break;
		}
	}

	return 0;
}
int DelClientIp(struct sockaddr_in TmpAddr)
{
	int i = 0;

	for(i = 0;i < 100;++i)
	{
		if(0 == memcmp(&TmpAddr,&ClientIpList[i].addr,sizeof(TmpAddr)))
		{
			ClientIpList[i].mark = 0;
			break;
		}
	}

	return 0;
}

int BoardcastClientIp(int sockfd,struct sockaddr_in TmpAddr,struct msgbuf TmpMes)
{
	int i = 0;
	ssize_t nsize = 0;
	for(i = 0;i < 100;++i)
	{
		if(ClientIpList[i].mark == 0)
		{
			continue;
		}

		if(0 != memcmp(&TmpAddr,&ClientIpList[i].addr,sizeof(TmpAddr)))
		{
			nsize = sendto(sockfd,&TmpMes,sizeof(TmpMes),0,(struct sockaddr *)&ClientIpList[i].addr,sizeof(ClientIpList[i].addr));
			if(-1 == nsize)
			{
				continue;
			}
		}
	}

	return 0;
}


int main(void)
{
	int sockfd = 0;
	int ret = 0;
	ssize_t nsize = 0;
	struct msgbuf recvmes;
	struct sockaddr_in recvaddr;
	struct sockaddr_in sendaddr;
	socklen_t addrlen = sizeof(sendaddr);

	recvaddr.sin_family = AF_INET;
	recvaddr.sin_port = htons(RECV_PORT);
	recvaddr.sin_addr.s_addr = INADDR_ANY;

	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (-1 == sockfd)
	{
		perror("fail to socket");
		return -1;
	}
	
	ret = bind(sockfd, (struct sockaddr *)&recvaddr, sizeof(recvaddr));
	if (-1 == ret)
	{
		perror("fail to bind");
		return -1;
	}

	memset(&ClientIpList,0,sizeof(ClientIpList));
	while (1)
	{
		memset(&recvmes, 0, sizeof(recvmes));
		nsize = recvfrom(sockfd, &recvmes, sizeof(recvmes), 0,(struct sockaddr *)&sendaddr, &addrlen);
		if (-1 == nsize)
		{
			perror("fail to recvfrom");
			return -1;
		}
		
		
		if(recvmes.type == MSG_TYPE_START)
		{
			AddClientIp(sendaddr);
			recvmes.type = MSG_TYPE_CHAT;
			sprintf(recvmes.text,"%s",recvmes.name);
		}
		else if (recvmes.type == MSG_TYPE_END)
		{
			DelClientIp(sendaddr);
			recvmes.type = MSG_TYPE_CHAT;
			sprintf(recvmes.text,"%s",recvmes.name);
		}
		
		if (recvmes.type == MSG_TYPE_CHAT)
		{
			BoardcastClientIp(sockfd,sendaddr,recvmes);
		}
	}

	close(sockfd);

	return 0;
}

结果：