APUE学习笔记 进程间通信 消息队列

comm.h文件内容如下：
#ifndef COMM_H
#define COMM_H
#define KEYPATH "/etc/hosts"
#define KEYPROJ 's'
#define NAMESIZE 64
#define NAMESIZE 64
struct score_st
{
        long mtype;
        char name[NAMESIZE];
        int math;
        int chinese;
};
#endif
rcv.c文件内容如下：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <string.h>
#include "comm.h"
int main()
{
        struct score_st rbuf;
        int i, ret;
        key_t key;
        int msgid;
        key = ftok(KEYPATH, KEYPROJ);
        if(key < 0)
        {
                perror("ftok() error");
                exit(1);
        }
        for(i = 0; i < 5; ++i)
        {
                msgid = msgget(key, IPC_CREAT|0600);
                if(msgid < 0)
                {
                        perror("msgget() error" );
                        exit(1);
                }
                if(msgrcv(msgid, &rbuf, sizeof(rbuf) - sizeof(long), 0, 0) < 0)
                {
                        perror("msgrcv() error");
                        exit(1);
                }
                printf("========================\n");
                printf("Name: %s\n", rbuf.name);
                printf("Math: %d\n", rbuf.math);
                printf("Chinese: %d\n", rbuf.chinese);
                printf("========================\n");
        }
                msgctl(msgid, IPC_RMID, 0);
                exit(0);
}

snd.c文件内容如下：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/ipc.h>
#include <sys/types.h>
#include <sys/msg.h>
#include "comm.h"
int main()
{
        int ret;
        key_t key;
        int msgid;
        struct score_st sbuf;
        key = ftok(KEYPATH, KEYPROJ);
        if(key < 0)
        {
                perror("ftok() error");
                exit(1);
        }
        msgid = msgget(key, 0);
        if(msgid < 0)
        {
                perror("msgget() error");
                exit(1);
        }
        sbuf.mtype = 1;
        strcpy(sbuf.name, "Zhangsan");
        sbuf.math = rand()%150;
        sbuf.chinese = rand()%150;
        ret = msgsnd(msgid ,&sbuf, sizeof(sbuf)-sizeof(long), 0);
        if(ret < 0)
        {
                perror("msgsnd() error");
                exit(1);
        }
        puts("OK");
        exit(0);
}