[Linux学习]Linux下进程通讯之共享内存

本文用两份代码，一个创建共享内存并向其中写入相关的数据，一个获取共享内存并读取其中的数据，下面上代码：

server.c：获取共享内存，并向共享内存中写入数据

#include <sys/types.h>  
#include <sys/ipc.h>  
#include <sys/shm.h>  
#include <stdio.h>  
  
#define BUF_SIZE 1024  
#define MYKEY 25  

struct st_person
{
    int age;
    char name[10];
};

int main()  
{
    int shmid;  
    struct st_person *shmptr;  
    //申请共享内存
    if((shmid = shmget(MYKEY,BUF_SIZE,IPC_CREAT)) ==-1)  
    {  
        printf("shmget error \n");  
        exit(1);  
    }  
    //连接共享内存
    if((shmptr = (struct st_person*)shmat(shmid,0,0))==(void *)-1)  
    {  
        printf("shmat error!\n");  
        exit(1);  
    }  
    //向共享内存写入信息
    shmptr->age = 10;
    memcpy(shmptr->name,"alephsoul", sizeof(char)*10);
    printf("age:%d\n", shmptr->age);
    printf("name:%s\n", shmptr->name);
    //解绑内存
    shmdt(shmptr);

    scanf("%s",shmptr);  
  
    exit(0);  
}  

client.c：获取server.c创建的共享内存，并读取server.c向共享内存中写入的数据。

#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>

#define BUF_SIZE 1024
#define MYKEY 25

struct st_person
{
    int age;
    char name[];
};

int  main()  
{  
    int shmid;  
    struct st_person *shmptr;  

    if((shmid = shmget(MYKEY,0,0)) == -1)  
    {  
        printf("shmget error!\n");  
        exit(1);  
    }  

    if((shmptr = (struct st_pesrson*)shmat(shmid,0,0)) == (void *)-1)  
    {  
        printf("shmat error!\n");  
        exit(1);  
    }  
    
    while(1)  
    {
    printf("age:%d;\n", shmptr->age);
    printf("name:%s\n;", shmptr->name); 
      sleep(3);  
    }  
    exit(0);  
}