用消息队列编写一个客户端服务器通信的程序
实验原理：
本实验用消息队列设计一个简易的双人聊天程序（一个服务器，两个客户端）。消息队列重点在于消息类型的匹配，客户端和服务端的“通信协议”的设计。思想如下：
服务器端：接受客户端发来的任何消息，并根据器消息类型，转发给对应的客户端。同时，检测是否有退出标记，有则给所有的客户端发送退出标记，等待1s后，确定客户端都退出，删除消息队列，释放空间，并退出。
客户端：A和B。A给B发送信息，先发给服务器，由服务器根据自定义协议转发该消息给B。同时B也可以通过服务器给A发消息
服务器：
#include
#include
#include
#include
#include
#define KEY_MSG 0x101
#define MSGSIZE 64
typedef struct
{
long mtype;
char mtext[MSGSIZE];
}msgbuf;
#define LEN sizeof(msgbuf)-sizeof(long)
void main()
{
int msgid;
msgbuf buf1,buf2;
msgid=msgget(KEY_MSG,IPC_CREAT|0666);
while(1)
{
msgrcv(msgid,&buf1,LEN,1L,0);
printf("Receive client1 message:%s\n",buf1.mtext);
if(buf1.mtext[0]=='x' || buf1.mtext[0]=='X')
{
strcpy(buf1.mtext,"x");
buf1.mtype=3L;
msgsnd(msgid,&buf1,LEN,0);
buf1.mtype=4L;
msgsnd(msgid,&buf1,LEN,0);
break;
}
buf1.mtype=4L;
msgsnd(msgid,&buf1,LEN,0);
msgrcv(msgid,&buf2,LEN,2L,0);
printf("Receive client2 message:%s\n",buf2.mtext);
if(buf2.mtext[0]=='x' || buf2.mtext[0]=='X')
{
strcpy(buf2.mtext,"x");
buf2.mtype=3L;
msgsnd(msgid,&buf2,LEN,0);
buf2.mtype=4L;
msgsnd(msgid,&buf2,LEN,0);
break;
}
buf2.mtype=3L;
msgsnd(msgid,&buf2,LEN,0);
}
sleep(1);
msgctl(msgid,IPC_RMID,NULL);
}
客户端1：
#include
#include
#include
#include
#include
#define KEY_MSG 0x101
#define MSGSIZE 64
typedef struct
{
long mtype;
char mtext[MSGSIZE];
}msgbuf;
#define LEN sizeof(msgbuf)-sizeof(long)
void main()
{
int msgid;
msgbuf buf1,buf2;
msgid=msgget(KEY_MSG,0666);
while(1)
{
printf("Input the mag to client2");
gets(buf1.mtext);
buf1.mtype=1L;
msgsnd(msgid,&buf1,LEN,0);
msgrcv(msgid,&buf2,LEN,3L,0);
if(buf2.mtext[0]=='x'||buf2.mtext[0]=='X')
{
printf("client1 will quit\n");
break;
printf("Recevie from client2,message:%s\n",buf2.mtext);
}
}
}
客户端2：
#include
#include
#include
#include
#include
#define KEY_MSG 0x101
#define MSGSIZE 64
typedef struct
{
long mtype;
char mtext[MSGSIZE];
}msgbuf;
#define LEN sizeof(msgbuf)-sizeof(long)
void main()
{
int msgid;
msgbuf buf1,buf2;
msgid=msgget(KEY_MSG,0666);
while(1)
{
msgrcv(msgid,&buf2,LEN,4L,0);
if(buf2.mtext[0]=='x'||buf2.mtext[0]=='X')
{
printf("client2 will quit!\n");
break;
}
else printf("Receive from client1,message:%s\n",buf2.mtext);
sleep(1);
printf("Input the msg to clinet1:");
gets(buf1.mtext);
buf1.mtype=2L;
msgsnd(msgid,&buf1,LEN,0);
}
}