共享主存实现进程间通信

写程序

 

#include"sys/ipc.h"
#include"sys/shm.h"
#include"sys/types.h"
#include"unistd.h"
#include"stdio.h"
#include"string.h"
typedef struct{
    char name[4];
    int age;
}people;

main(int argc,char** argv)
{
    int shm_id,i;
    key_t key;
    char temp;
    people *p_map;
    char* name="..";
    key=ftok(name,0);
    if(key==-1)
        perror("ftok error!");
    shm_id=shmget(key,4096,IPC_CREAT|0666);
    if(shm_id==-1)
    {
        perror("shmget error!");
        return;
    }
    p_map=(people*)shmat(shm_id,NULL,0);
    temp='a';
    for(i=0;i<10;i++)
    {
        temp++;
        memcpy((*(p_map+i)).name,&temp,1);
        (*(p_map+i)).age=20+i;
    }
    if(shmdt(p_map)==-1)
        perror("detach error!");
}

读程序

 

#include"sys/ipc.h"
#include"sys/shm.h"
#include"sys/types.h"
#include"unistd.h"
#include"stdio.h"
typedef struct{
    char name[4];
    int age;
}people;

main(int argc,char** argv)
{
    int shm_id,i;
    key_t key;
    //char temp;
    people *p_map;
    char* name="..";
    key=ftok(name,0);
    if(key==-1)
        perror("ftok error!");
    shm_id=shmget(key,4096,IPC_CREAT|0666);
    if(shm_id==-1)
    {
        perror("shmget error!");
        return;
    }
    p_map=(people*)shmat(shm_id,NULL,0);
    //temp='a';
    for(i=0;i<10;i++)
    {
        printf("name:%s\n",(*(p_map+i)).name);
        printf("age %d\n",(*(p_map+i)).age);
    }
    if(shmdt(p_map)==-1)
        perror("detach error!");
}