C++ での共有メモリとメッセージ キューの使用

#include <sys/shm.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
    int shmid;
    char *shmaddr;

    shmid = shmget((key_t)1234, sizeof(char)*100, 0666 | IPC_CREAT);
    if(shmid == -1){
        perror("shmget failed");
        exit(EXIT_FAILURE);
    }

    shmaddr = (char*) shmat(shmid, (void*)0, 0);
    if(shmaddr == (char*)-1){
        perror("shmat failed");
        exit(EXIT_FAILURE);
    }

    sprintf(shmaddr, "Hello shared memory!");

    printf("Message is written in shared memory: %s
", shmaddr);

    shmdt(shmaddr);

    return 0;
}

#include <sys/msg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct{
    long msg_type;
    char msg_text[100];
} msg_buf;

int main()
{
    int msgid;
    msg_buf msg;

    msgid = msgget((key_t)1234, 0666 | IPC_CREAT);
    if(msgid == -1){
        perror("msgget failed");
        exit(EXIT_FAILURE);
    }

    msg.msg_type = 1;
    strcpy(msg.msg_text, "Hello message queue!");

    if(msgsnd(msgid, (void*)&msg, sizeof(msg_buf), 0) == -1){
        perror("msgsnd failed");
        exit(EXIT_FAILURE);
    }

    memset(&msg, 0, sizeof(msg_buf));

    if(msgrcv(msgid, (void*)&msg, sizeof(msg_buf), 0, 0) == -1){
        perror("msgrcv failed");
        exit(EXIT_FAILURE);
    }

    printf("Message received from message queue: %s
", msg.msg_text);

    if(msgctl(msgid, IPC_RMID, 0) == -1){
        perror("msgctl failed");
        exit(EXIT_FAILURE);
    }

    return 0;
}