消息队列 两个进程

参考地址：http://blog.csdn.net/zhsp1029/article/details/2171462

/*msgserver.c*/

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/stat.h>

#define   MSG_FILE "/tmp/msg_logs"
#define   BUFFER 255
#define   PERM S_IRUSR|S_IWUSR
/* 服务端创建的消息队列最后没有删除,我们要使用ipcrm命令来删除的 */
/* ipcrm -q <msqid> */

struct msgtype {
    long mtype;
    char buffer[BUFFER+1];
};

int main()
{
    struct msgtype msg;
    key_t key;
    int msgid;

    if((key=ftok(MSG_FILE,'a'))==-1)
    {
        printf("Creat Key Error:%s/n", strerror(errno));
        exit(1);
    }

    if((msgid=msgget(key, PERM|IPC_CREAT|IPC_EXCL))==-1)
    {
        printf("Creat Message Error:%s/n", strerror(errno));
        exit(1);
    }
    printf("msqid = %d/n", msgid);

    //while(1)
    {
        msgrcv(msgid, &msg, sizeof(struct msgtype), 1, 0);
        printf("Server Receive:%s/n", msg.buffer);
        msg.mtype = 2;
        msgsnd(msgid, &msg, sizeof(struct msgtype), 0);
        if((msgctl(msgid,IPC_RMID,NULL))<0){              //删除消息
                perror("msgctl");
                exit(1);
            }
    }


    exit(0);
}

/* msgclient.c */

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

#define   MSG_FILE "/tmp/msg_logs"
#define   BUFFER 255
#define   PERM S_IRUSR|S_IWUSR

struct msgtype {
    long mtype;
    char buffer[BUFFER+1];
};

int main(int argc, char **argv)
{
    struct msgtype msg;
    key_t key;
    int msgid;

    if(argc != 2)
    {
        fprintf(stderr,"Usage:%s string/n", argv[0]);
        exit(1);
    }

    if((key=ftok(MSG_FILE,'a'))==-1)
    {
        fprintf(stderr,"Creat Key Error:%s/n", strerror(errno));
        exit(1);
    }

    if((msgid=msgget(key, PERM))==-1)
    {
        fprintf(stderr,"Creat Message  Error:%s/n", strerror(errno));
        exit(1);
    }

    msg.mtype = 1;
    strncpy(msg.buffer, argv[1], BUFFER);
    msgsnd(msgid, &msg, sizeof(struct msgtype), 0);
    memset(&msg, '/0', sizeof(struct msgtype));
    msgrcv(msgid, &msg, sizeof(struct msgtype), 2, 0);
    fprintf(stderr, "Client receive:%s/n", msg.buffer);
    exit(0);
}

完