给以下代码写注释：#include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <sys/shm.h> #define MAXSIZE 1024 struct shm{ int write; //记录读进程是否已经将内容读取 char buffer[MAXSIZE]; }; int main() { int shmid; struct shm *share; void *shmptr = NULL; if(shmid = shmget(0X44,MAXSIZE,0666|IPC_CREAT) < 0) perror("shmget"); if((shmptr = shmat(shmid,0,0)) == (void *)-1) perror("shmat"); printf("Read process:\n"); share = (struct shm *)shmptr; while(1) { if(share->write != 0) { if(!strncmp(share->buffer,"end\n",3) == 0) { printf("%s",share->buffer); share->write = 0; } else break; } } if(shmdt(shmptr) < 0) perror("shmdt"); exit(0); }//lijiadi202131060520

注释如下：

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/shm.h>
#define MAXSIZE 1024 // 定义共享内存的最大大小

// 定义共享内存结构体
struct shm{
    int write; // 记录读进程是否已经将内容读取
    char buffer[MAXSIZE];
};

int main() {
    int shmid; // 共享内存的标识符
    struct shm *share; // 共享内存的指针
    void *shmptr = NULL; 

    // 创建共享内存
    if(shmid = shmget(0X44,MAXSIZE,0666|IPC_CREAT) < 0) 
        perror("shmget");

    // 连接共享内存
    if((shmptr = shmat(shmid,0,0)) == (void *)-1) 
        perror("shmat");

    printf("Read process:\n");
    share = (struct shm *)shmptr;

    // 循环读取共享内存中的数据
    while(1) { 
        if(share->write != 0) 
        { 
            if(!strncmp(share->buffer,"end\n",3) == 0) 
            { 
                printf("%s",share->buffer); 
                share->write = 0; // 将读进程是否已经将内容读取的标志置为0
            } 
            else 
                break; // 如果读取到了"end\n"，则退出循环
        } 
    } 

    // 断开共享内存
    if(shmdt(shmptr) < 0) 
        perror("shmdt");

    exit(0); // 退出程序
}