linux shm 进程之间内存共享

进程之间内存共享
实例代码如下:
服务器端:

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

#define SHM_SIZE 26

int main(int argc,char* argv[])
{
    char* pMem = NULL;
    int shmid = 0;
    int i = 0;
    int retcode = 0;
    key_t key=ftok("/home/root",2);

    shmid = shmget(key, SHM_SIZE, IPC_CREAT|0600);
    if(shmid == -1)
    {
        perror("shmget");
        exit(-1);
    }

    pMem = (char*)shmat(shmid, NULL, 0);
    if(pMem == (char*)-1)
    {
        perror("shmat");
        exit(-1);
    }
    printf("SharedMemory:%p\n",pMem);
    for(i=0;i<SHM_SIZE;i++)
    {
        pMem[i]='a'+i;
    }

    while(pMem[0]!='*')
        sleep(1);

    retcode = shmdt(pMem);
    if(retcode == -1)
    {
        perror("shmdt");
        exit(-1);
    }
    retcode = shmctl(shmid, IPC_RMID, NULL);
    if(retcode == -1)
    {
        perror("shmctl");
        exit(-1);
    }

    return 0;
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
客户端:

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

#define SHM_SIZE 26

int main(int argc, char* argv[])
{
    int i = 0;
    char* pMem = NULL;
    key_t key = ftok("/home/root", 2);
    int shmid = shmget(key, SHM_SIZE, 0600);
    if(shmid == -1)
    {
        perror("shmget");
        exit(-1);
    }
    pMem = (char*)shmat(shmid,NULL,0);
    if(pMem == (char*)-1)
    {
        perror("shmat");
        exit(-1);
    }
    printf("Client:SharedMemoryat%p\n", pMem);
    for(i=0; i<SHM_SIZE; i++)
    {
        putchar(pMem[i]);
    }
    putchar('\n');
    pMem[0]='*';
    shmdt(pMem);

    return 0;
}

转载自: http://hi.baidu.com/jiangxun_lin/blog/item/9ae6703244df8abf5fdf0ef9.html