linux下C语言内存共享

write.c

/* write.c */

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

#define SHM_SIZE 1024

int main()
{
    int shmid;
    char *shmaddr;
    char write_buf[SHM_SIZE];

    // 创建共享内存段
    shmid = shmget((key_t)1234, SHM_SIZE, 0666|IPC_CREAT);
    if (shmid == -1) {
        perror("shmget failed");
        exit(EXIT_FAILURE);
    }

    // 将共享内存段连接到当前进程
    shmaddr = (char*)shmat(shmid, 0, 0);
    if (shmaddr == (void*)-1) {
        perror("shmat failed");
        exit(EXIT_FAILURE);
    }

    // 从标准输入读取数据并将其写入共享内存
    while(1) {
        fgets(write_buf, SHM_SIZE, stdin);
        strncpy(shmaddr, write_buf, SHM_SIZE);
        if (strncmp(write_buf, "exit", 4) == 0) {
            break;
        }
    }

    // 断开共享内存连接
    if (shmdt(shmaddr) == -1) {
        perror("shmdt failed");
        exit(EXIT_FAILURE);
    }

    // 删除共享内存段
    if (shmctl(shmid, IPC_RMID, 0) == -1) {
        perror("shmctl failed");
        exit(EXIT_FAILURE);
    }
    
    printf("write exit\n");

    return 0;
}

read.c

/* read.c */

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

#define SHM_SIZE 1024

int main()
{
    int shmid;
    char *shmaddr;
    char read_buf[SHM_SIZE];

    // 获取共享内存段
    shmid = shmget((key_t)1234, SHM_SIZE, 0666|IPC_CREAT);
    if (shmid == -1) {
        perror("shmget failed");
        exit(EXIT_FAILURE);
    }

    // 将共享内存段连接到当前进程
    shmaddr = (char*)shmat(shmid, 0, 0);
    if (shmaddr == (void*)-1) {
        perror("shmat failed");
        exit(EXIT_FAILURE);
    }

    // 从共享内存读取数据并输出到标准输出
    while(1) {
        strncpy(read_buf, shmaddr, SHM_SIZE);
        printf("Received message: %s\n", read_buf);
        if (strncmp(read_buf, "exit", 4) == 0) {
            printf("Received exit\n");
            break;
        }
        sleep(1);
    }

    // 断开共享内存连接
    if (shmdt(shmaddr) == -1) {
        perror("shmdt failed");
        exit(EXIT_FAILURE);
    }

    printf("read exit\n");
    
    return 0;
}