IPC Shared Memory

tsShmRd.c

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

int main()
{
    int shmid;
    char *ptr;
    
    shmid=shmget(0x90,1024,SHM_W|SHM_R|IPC_EXCL);    //根据key获取共享内存ID

    if(-1==shmid)
    {
        perror("create share memory");
    }

    ptr=(char*)shmat(shmid,0,0);    //获取共享内存首地址
    if((void *)-1==ptr)
    {
        perror("get share memory");
    }
    printf("share memory:%s\n",ptr);     //打印数据

    shmdt(ptr);     //分离共享内存
    
    if (shmctl(shmid, IPC_RMID, 0) == -1)     //释放内存
    {
        perror("shmctl(IPC_RMID) failed\n");
		return -1;
    }
    
    return 0;
}

tsShmWr.c

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

int main()
{
    int shmid;
    char *ptr;
    char *shm_str="this is a share memory";
    shmid=shmget(0x90,1024,SHM_W|SHM_R|IPC_CREAT|IPC_EXCL);    //创建共享内存

    if(-1==shmid)
    {
        perror("create share memory");
    }

    ptr=(char*)shmat(shmid,0,0);    //获取共享内存首地址
    if((void *)-1==ptr)
    {
        perror("get share memory");
    }
    strcpy(ptr,shm_str);    //写入数据
    shmdt(ptr);     //分离共享内存

    return 0;
}