进程间消息队列通信

要保证server能够接收client的消息，就必须保证server的生成的msg的标识符是一样的，也就是两个用的key是必须一样的。

msgLucy.c

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

#define PROJID 0XFF
#define LUCY 1
#define PETER 2
#define SEED 'g'

int mqid;
void terminate_handler(int );

void terminate_handler(int signo)
{
msgctl(mqid,IPC_RMID,NULL);/*delete the data*/
exit(0);
}

int main()
{
//char filenm[]="msg";
key_t mqkey;
struct msgbuf
{
    long mtype;
    char mtext[256];
    int * m;
}msg;
int ret;

mqkey = ftok(".",SEED);/*get the same key*/
if(mqkey==-1)
{
    perror("ftok error:");
    exit(-1);
}

mqid = msgget(mqkey,IPC_CREAT|0666);/*if not creat or open it*/
if(mqid==-1)
{
    perror("msgget error:");
    exit(-1);
}

signal(SIGINT,terminate_handler);
signal(SIGTERM,terminate_handler);

while(1)
{
    printf("Lucy:");
    fgets(msg.mtext,256,stdin);
    if(strncmp("quit",msg.mtext,4)==0)
    {
    msgctl(mqid,IPC_RMID,NULL);
    exit(0);
    }
    //printf("IPC_NOWAIT=%d\n",IPC_NOWAIT);
    msg.mtext[strlen(msg.mtext)-1] = '\0';
    msg.mtype = LUCY;
    msgsnd(mqid,&msg,strlen(msg.mtext)+1,0);/*block method*/
    msgrcv(mqid,&msg,sizeof(struct msgbuf),PETER,0);/*can recieve the address*/
    printf("Peter:%s\n",msg.mtext);
    printf("the ponit m:%p\n",msg.m);
}
}

msgPeter.c

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

#define PROJID 0XFF
#define LUCY 1
#define PETER 2
#define SEED 'g'

void terminate_handler(int );

int mqid;

void terminate_handler(int signo)
{
msgctl(mqid,IPC_RMID,NULL);
exit(0);
}

int main()
{
//char filenm[]="msg";
//int mqid;
key_t mqkey;
int n;
struct msgbuf
{
    long mtype;
    char mtext[256];
    int * m;
}msg;
int ret;

mqkey = ftok(".",SEED);
if(mqkey==-1)
{
    perror("ftok error:");
    exit(-1);
}

if((mqid = msgget(mqkey,0))==-1)
{
printf("come here!!!!!!!!!!!!!!\n");/*if not creat and come here or open it*/
mqid = msgget(mqkey,IPC_CREAT|0666);
}
//mqid = msgget(mqkey,0);
if(mqid==-1)
{
    perror("msgget error:");
    exit(-1);
}
n=4;
msg.m=&n;

printf("the ponit m:%p\n",msg.m);
printf("msg.m's value is %d\n",*(msg.m));

signal(SIGINT,terminate_handler);
signal(SIGTERM,terminate_handler);

while(1)
{
    msgrcv(mqid,&msg,sizeof(struct msgbuf),LUCY,0);
    printf("LUCY:%s\n",msg.mtext);
    printf("Peter:");
    fgets(msg.mtext,256,stdin);
    if(strncmp("quit",msg.mtext,4)==0)
    {
    msgctl(mqid,IPC_RMID,NULL);
    exit(0);
    }
    msg.mtext[strlen(msg.mtext)-1] = '\0';
    msg.mtype = PETER;
    msgsnd(mqid,&msg,sizeof(struct msgbuf),0);/*can send the address to the server*/
}
}