Передача через msgsnd и msgrecv сложной структуры

//---------------- mymsg.c
#ifndef __MYMSG_H__
#define __MYMSG_H__

#include<string.h>
#include<time.h>
#include<sys/ipc.h>
#include<sys/msg.h>
#include<sys/errno.h>

#define MSGPERM 0600    // msg queue permission
#define MSGTXTLEN 128   // msg text length
#define MSGKEY 32769
struct msg_buf {
  long mtype;
  char mtext[MSGTXTLEN];
  int len;
} msg;
#endif

//---------------- send.c
#include <stdio.h>
#include "mymsg.h"

#include <sys/types.h>
#include <unistd.h>

//extern int errno;

int get_queue_ds( int qid, struct msqid_ds *qbuf )
{
    if( msgctl( qid, IPC_STAT, qbuf) == -1){
                return(-1);
    }
    return(0);
}

int main(int argc, char **argv)
{
    int msgqid, rc;

    msgqid = msgget(MSGKEY, MSGPERM|IPC_CREAT|IPC_EXCL);
    if (msgqid < 0) {
        perror(strerror(errno));
        printf("failed to create message queue with msgqid = %d\n", msgqid);
        return 1;
    } else
        printf("message queue %d created\n",msgqid);

    // message to send
    msg.mtype = 1; // set the type of message
    msg.len = sizeof(msg)-sizeof(long);//getpid();
    sprintf (msg.mtext, "%s\n", "a text msg..."); /* setting the right time format by means of ctime() */
    printf ("a len msg = %d\n", msg.len); /* setting the right time format by means of ctime() */

  // send the message to queue
    rc = msgsnd(msgqid, &msg, sizeof(msg)-sizeof(long), 0); // the last param can be: 0, IPC_NOWAIT, MSG_NOERROR, or IPC_NOWAIT|MSG_NOERROR.
    if (rc < 0) {
        perror( strerror(errno) );
        printf("msgsnd failed, rc = %d\n", rc);
        return 1;
    } else
        printf("Message send done!\n");

    return 0;
}

//---------------- recv.c
#include <stdio.h>
#include "mymsg.h"
int main(int argc, char **argv)
{
    int msgqid, rc;

    msgqid = msgget(MSGKEY, MSGPERM|IPC_EXCL);
    if (msgqid < 0) {
        perror(strerror(errno));
        printf("failed to create message queue with msgqid = %d\n", msgqid);
        return 1;
    } else
        printf("message queue %d created\n", msgqid);
    // read the message from queue
    rc = msgrcv(msgqid, &msg, sizeof(msg)-sizeof(long), 0, 0);
    if (rc < 0) {
        perror( strerror(errno) );
        printf("msgrcv failed, rc=%d\n", rc);
        return 1;
    }
    printf("received msg: %s\n", msg.mtext);
    printf("received len: %d\n", msg.len);

    // remove the queue
    rc=msgctl(msgqid,IPC_RMID,NULL);
    if (rc < 0) {
        perror( strerror(errno) );
        printf("msgctl (return queue) failed, rc=%d\n", rc);
        return 1;
    }
    printf("message queue %d is gone\n",msgqid);
    return 0;
}