进程间通信_05消息队列

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
int msgget(key_t key,              //key值，标识消息队列的唯一性
                   int msgflg);    //设置消息队列的属性。一般为 0666 | IPC_CREAT
//返回值：>0（成功，消息队列的标识符） -1（创建失败，失败信息见errno）

#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/types.h>
int msgsnd(int msqid,                  //消息队列的标识符
                   const void *msgp,   //包含数据的结构体指针
                   size_t msgsz,       //结构体中数据的长度
                   int msgflg);        //用于设置发送数据时的一些特性
//返回值： 0（写数据成功）  -1（写数据失败，错误信息见errno）

struct msgbuf {
    long mtype;         /* message type, must be > 0 */
    char mtext[1];      /* message data */
};

       #include <sys/types.h>
       #include <sys/ipc.h>
       #include <sys/msg.h>
       ssize_t msgrcv(int msqid,                     //消息队列的标识符
                                void *msgp,          //接收消息存放的容器
                                size_t msgsz,        //接收消息的大小
                                long msgtyp,         //接收消息的消息类型
                                int msgflg);         //设置接收消息时的一些特性
//返回值：>0 (成功读取到的数据大小)  -1(失败，错误信息见errno)

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
int msgctl(int msqid,                             //消息队列的标识符
                  int cmd,                        //对消息队列属性的操作
                  struct msqid_ds *buf);          //消息队列的属性
//返回值：0(成功)  -1(失败，失败信息见errno)

struct msqid_ds {
    struct ipc_perm msg_perm;        /* Ownership and permissions */
    time_t msg_stime;                /* Time of last msgsnd(2) */
    time_t msg_rtime;                /* Time of last msgrcv(2) */
    time_t msg_ctime;                /* Time of last change */
    unsigned long __msg_cbytes;      /* Current number of bytes in  queue (non-standard) */ 
    msgqnum_t msg_qnum;              /* Current number of messages  in queue */ 
    msglen_t msg_qbytes;             /* Maximum number of bytes  allowed in queue */ 
    pid_t msg_lspid;                 /* PID of last msgsnd(2) */
    pid_t msg_lrpid;                 /* PID of last msgrcv(2) */
};

struct ipc_perm {
    key_t __key;                      /* Key supplied to msgget(2) */
    uid_t uid;                        /* Effective UID of owner */
    gid_t gid;                        /* Effective GID of owner */
    uid_t cuid;                       /* Effective UID of creator */
    gid_t cgid;                       /* Effective GID of creator */
    unsigned short mode;              /* Permissions */
    unsigned short __seq;             /* Sequence number */
};

/*************************************************************************
    > File Name: testmsgqueueW.c
    > Author: qiaozp
    > Mail: qiaozongpeng@163.com
    > Created Time: 2014-9-19 17:15:09
    > Step: 1 连接消息队列
            2 读数据
 ************************************************************************/
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <errno.h>
using namespace std;

#define KEY 1234
#define MAX_BUFF_SIZE 512

typedef struct {
    long mtype;         
    char mtext[MAX_BUFF_SIZE];      
}_msgbuf;

int main()
{
    //1 创建消息队列
    int msgid = 0;
    if((msgid = msgget((key_t)KEY, 0666|IPC_CREAT)) == -1)
    {
        cout << "创建key值为[" << KEY << "]的消息队列失败" << endl;
        return -1;
    }
    
    _msgbuf buff;
    //2 向消息队列中写数据
    while(1)
    {
        cout << "请输入要放入消息内存中的数据：";
        scanf("%s", buff.mtext);
        
        if(msgsnd(msgid, (void*)&buff, MAX_BUFF_SIZE, 0) == -1)
        {
            cout << "向key值为[" << KEY << "]的消息队列发送数据失败" << endl;
            return -1;
        }
        
        if(strncasecmp(buff.mtext, "end", strlen("end")) == 0)
        {
            //结束的时候删除消息队列
            if(msgctl(msgid, IPC_RMID, NULL) == -1)
            {
                cout << "删除key值为[" << KEY << "]的消息队列失败" << endl;
                return -1;
            }
            break;
        }
    }
    
    return 0;
}

/*************************************************************************
    > File Name: testmsgqueueR.c
    > Author: qiaozp
    > Mail: qiaozongpeng@163.com
    > Created Time: 2014-9-19 17:15:28
    > Step: 1 创建消息队列
            2 写数据
            3 end退出
 ************************************************************************/
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <errno.h>
using namespace std;

#define KEY 1234
#define MAX_BUFF_SIZE 512

typedef struct {
    long mtype;         
    char mtext[MAX_BUFF_SIZE];      
}_msgbuf;

int main()
{
    //1 创建消息队列
    int msgid = 0;
    if((msgid = msgget((key_t)KEY, 0666|IPC_CREAT)) == -1)
    {
        cout << "创建key值为[" << KEY << "]的消息队列失败" << endl;
        return -1;
    }
    
    _msgbuf buff;
    //2 向消息队列中写数据
    cout << "开始从消息队列中获取数据，请在服务端输入数据..." << endl;
    while(1)
    {
        if(msgrcv(msgid, (void*)&buff, MAX_BUFF_SIZE, 0, 0) == -1)
        {
            cout << "从key值为[" << KEY << "]的消息队列获取数据失败" << endl;
            return -1;
        }
        cout << "获取到的数据为 : " << buff.mtext << endl;
        
        if(strncasecmp(buff.mtext, "end", strlen("end")) == 0)
        {
            cout << "退出." << endl;
            break;
        }
    }
    
    return 0;
}