client2.c

在linux下利用消息队列实现简单的聊天程序

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>

#define BUFSZ 512

struct message
{
	long msg_type;
	char msg_text[BUFSZ];
};

int main()
{
	int i,j;
    	pid_t  pid;
    	int    qid;
	key_t  key;
	int    len;
	struct message msg;
	/*根据不同的路径和关键表示产生标准的key*/
	if ( (key=ftok(".",'a')) == -1 )
	{
		perror("ftok");
		exit(1);
	}
	/*创建消息队列*/
	if( (qid=msgget(key,IPC_CREAT|0666)) == -1 )
	{
		perror("msgget");
		exit(1);
	}
	printf("opened queue %d\n",qid);
	
	if( (pid=fork()) == -1 )
	{
		perror("fork");
		exit(-1);
	}
	if(pid==0)	
	{
	    	puts("Please enter the message to client1:");
	    	while(1)
		{
			if( (fgets( (&msg)->msg_text,BUFSZ,stdin)) == NULL )
			{
				puts("no message!\n");
				exit(1);
			}
			i = strcmp(msg.msg_text,"quit\n");
			if ( i == 0 )
			{
				msg.msg_type = 1 ;
			    	if( (msgsnd(qid,&msg,BUFSZ,0)) <0 )
				{
					perror("message posted!\n");
					exit(1);
				}
				sleep(1);
				kill(getppid(),SIGINT);
				exit(1);
			}
			else
			{
				msg.msg_type = 1 ;
				len = strlen(msg.msg_text);
				/*添加消息到消息队列*/
				if( (msgsnd(qid,&msg,BUFSZ,0)) <0 )
				{
					perror("message posted!\n");
					exit(1);
				}
				sleep(1);
			}
		}
	}
	else
	{
		while(1)
		{
			if(msgrcv(qid,&msg,BUFSZ,2,0) <0 )
			{
				perror("msgrcv");
				exit(1);
			}
			j = strcmp(msg.msg_text,"quit\n");
			if( j == 0 )
			{
				printf("Client1 exit!\n");
				printf("Exit in 1 second!\n");
				sleep(1);
				exit(1);
			}
			else
				printf("Receive message from client1:%s\n",(&msg)->msg_text);
		}
	}
}