2024.8.6 作业

1> 使用消息队列完成两个进程之间相互通信

snd.c

#include <myhead.h>struct msgbuf
{long mtype;char mtext[1024];
};#define SIZE sizeof(struct msgbuf)-sizeof(long)int main(int argc,const char *argv[])
{pid_t pid = fork();if(pid==-1){perror("fork error");return -1;}		else if(pid==0){//子进程key_t key = ftok("/",'k');int msqid = msgget(key,IPC_CREAT|0644);if(msqid==-1){perror("msgget error");return -1;}struct msgbuf buf;while(1)                  //接受类型2消息{msgrcv(msqid,&buf,SIZE,2,0);if(strcmp(buf.mtext,"quit")==0){break;}printf("收到消息:%s\n",buf.mtext);}exit(EXIT_SUCCESS);}//父进程key_t key = ftok("/",'k');int msqid = msgget(key,IPC_CREAT|0644);if(msqid==-1){perror("msgget error");return -1;}struct msgbuf buf;while(1)               //发送类型1消息{fgets(buf.mtext,SIZE,stdin);buf.mtext[strlen(buf.mtext)-1]=0;buf.mtype=1;msgsnd(msqid,&buf,SIZE,0);if(strcmp(buf.mtext,"quit")==0){break;}}wait(NULL);return 0;
}

recv.c

#include <myhead.h>struct msgbuf
{long mtype;char mtext[1024];
};#define SIZE sizeof(struct msgbuf)-sizeof(long)int main(int argc,const char *argv[])
{pid_t pid = fork();if(pid==-1){perror("fork error");return -1;}		else if(pid==0){//子进程key_t key = ftok("/",'k');int msqid = msgget(key,IPC_CREAT|0644);if(msqid==-1){perror("msgget error");return -1;}struct msgbuf buf;while(1)                   //发送类型2消息{fgets(buf.mtext,SIZE,stdin);buf.mtext[strlen(buf.mtext)-1]=0;buf.mtype=2;msgsnd(msqid,&buf,SIZE,0);if(strcmp(buf.mtext,"quit")==0){break;}}exit(EXIT_SUCCESS);}key_t key = ftok("/",'k');int msqid = msgget(key,IPC_CREAT|0644);if(msqid==-1){perror("msgget error");return -1;}struct msgbuf buf;while(1)                         //接受类型1消息{msgrcv(msqid,&buf,SIZE,1,0);if(strcmp(buf.mtext,"quit")==0){break;}printf("收到消息:%s\n",buf.mtext);}wait(NULL);if(msgctl(msqid,IPC_RMID,NULL)==-1){perror("msgctl error");return -1;}return 0;
}

2> 将共享内存的实现重新敲一遍

snd.c

#include<myhead.h>
#include<sys/user.h>int main(int argc, const char *argv[])
{//1、创建key值用于创建共享内存段key_t key = ftok("/", 't');if(key == -1){perror("ftok error");return -1;}printf("key = %d\n", key);//2、创建一个共享内存的对象int shmid = shmget(key, PAGE_SIZE, IPC_CREAT|0664);if(shmid == -1){perror("shmget error");return -1;}printf("shmid = %d\n", shmid);//3、将共享内存段映射到程序中来char *addr = (char *)shmat(shmid, NULL, 0);printf("addr = %p\n", addr);         //输出映射的地址//向共享内存中写入数据strcpy(addr, "hello a hua qing yuan jian\n");sleep(5);//取消映射关系if(shmdt(addr) ==-1){perror("shmdt error");return -1;}while(1);return 0;
}

recv.c

#include<myhead.h>
#include<sys/user.h>int main(int argc, const char *argv[])
{//1、创建key值用于创建共享内存段key_t key = ftok("/", 't');if(key == -1){perror("ftok error");return -1;}printf("key = %d\n", key);//2、创建一个共享内存的对象int shmid = shmget(key, PAGE_SIZE, IPC_CREAT|0664);if(shmid == -1){perror("shmget error");return -1;}printf("shmid = %d\n", shmid);//3、将共享内存段映射到程序中来char *addr = (char *)shmat(shmid, NULL, 0);printf("addr = %p\n", addr);         //输出映射的地址//读出共享内存中的数据printf("消息为：%s", addr);sleep(5);if(shmdt(addr) == -1){perror("shmdt error");return -1;}//删除共享内存if(shmctl(shmid, IPC_RMID, NULL) == -1){perror("shmctl error");return -1;}while(1);return 0;
}