发送队列消息

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

typedef struct
{
long int nType;
char szText[256];
}MSG;

int main(int argc, char** argv) {
    key_t IKey1;
    int nMsgId;
    MSG msg;
    if((IKey1 = ftok("/etc/profile",1)) == -1)
    {
        perror("ftok");
        exit(1);
    }
    if((nMsgId = msgget(IKey1,IPC_CREAT|IPC_EXCL|0666)) == -1)
    {
        if(errno != EEXIST)
        {
            perror("msgget");
            exit(2);
        }
        
        if((nMsgId = msgget(IKey1,0)) == -1)
        {
            perror("msgget");
            exit(3);
        }
    }
    printf("KeyID=%x\n",IKey1);
    printf("MsgID=%d\n",nMsgId);
    
    memset(&msg,0x00,sizeof(MSG));
    msg.nType = 2;
    memcpy(msg.szText,"123456",6);
    if(msgsnd(nMsgId,(const void*)&msg,strlen(msg.szText),IPC_NOWAIT)<0)
    {
        perror("msgsnd");
    }
   
    return 0;
}

运行结果， 2 为两个消息，12 为长度，666为rwx

[root@64 ~]# ipcs -q

------ Message Queues --------
key        msqid      owner      perms      used-bytes   messages    
0x010088c2 0          root       666        12           2           

[root@elm64 ~]#