进程间通信

骑猪看日落 2022-06-03 00:39 322阅读 0赞

**实现父子进程间的通信**

**介绍:  1 .以结构体为传输目标 ,先定义一个枚举类型存放消息类型,定义一个结构体 存放消息类型和该消息类型的结构体的大小,定义不同消息类型的消息的结构体**

**          父进程写入消息,子进程读取消息 **

**          2 .创建管道  父子进程,公有三个文件  pipe\_main.c   main函数文件 创建管道的  子父进程     pipe\_mes.h 文件   枚举的定义 结构体的定义 各种函数的声明**

**pipe\_mes.c    函数的实现**

**具体代码段;**

**pipe\_main.c:        **

#include<stdio.h> #include<stdlib.h> #include<string.h> #include<unistd.h> #include<errno.h> #include "pipe_mes.h" int main(int argc,char** argv) { int fd[2]; int pipe_result; if(pipe_result = pipe(fd)); if(pipe_result == -1) { printf("管道创建失败!\n"); exit(errno); } pid_t child_pid; child_pid = fork(); if(child_pid < 0){ printf("创建子进程失败!\n"); exit(errno); } else if(child_pid == 0){ //进入子进程 并接受来自父进程的消息 解析并打印 close(fd[1]); int i; for(i = 0; i < 3; i++) { HMessage hm = (HMessage) malloc (sizeof(Message)); read(fd[0],hm,sizeof(Message)); switch(hm->msg_kind) { case Type_1: { HMES_ONE M_ONE = ReadMes_ONE(fd[0],hm); printf("接收来自Type_1的消息: %d\n",M_ONE->num); } break; case Type_2: { HMES_TWO M_TWO = ReadMes_TWO(fd[0],hm); printf("接收来自Type_2的消息: %s\n",M_TWO->str); } break; case Type_3: { HMES_THREE M_THREE = ReadMes_THREE(fd[0],hm); printf("接收来自Type_3的消息:%d\t%s\n",M_THREE->num,M_THREE->str); } break; default: printf("不识别的消息类型.......请检查!\n"); break; } } _exit(0); } close(fd[0]); //调用发送消息函数 SendMes_ONE(fd[1],2017); SendMes_TWO(fd[1],"结束了!"); SendMes_THREE(fd[1],2018,"开始了"); return 0; }

**pipe\_mes.h**

#ifndef __MESSAGE_H__ #define __MESSAGE_H__ //消息类型 typedef enum KIND{ Type_1,Type_2,Type_3 }Msg_kind; //Message 是所有消息的共同首部 typedef struct Message{ Msg_kind msg_kind; size_t size; }Message,*HMessage; //消息 ONE typedef struct TMessage_1{ Message base; int num; }MES_ONE,*HMES_ONE; //消息 TWO typedef struct TMessage_2{ Message base; char str[1024]; }MES_TWO,*HMES_TWO; //消息 THREE typedef struct TMessage_THREE{ Message base; int num; char str[1024]; }MES_THREE,*HMES_THREE; //消息 ONE 接收和发送函数 HMES_ONE ReadMes_ONE(int in,HMessage hm); size_t SendMes_ONE(int out,int num); //消息 TWO 接受和发送 HMES_TWO ReadMes_TWO(int in,HMessage hm); size_t SendMes_TWO(int out,char* str); //消息 THREE 接受和发送 HMES_THREE ReadMes_THREE(int in,HMessage hm); size_t SendMes_THREE(int out,int num,char *str); #endif

**pipe\_mes.c**

#include<stdio.h> #include<stdlib.h> #include<string.h> #include<unistd.h> #include<errno.h> #include "pipe_mes.h" //消息 Type_1 size_t SendMes_ONE(int out,int num) { HMES_ONE Mes_One = (HMES_ONE) malloc (sizeof(MES_ONE)); Mes_One->base.msg_kind = Type_1; Mes_One->base.size = sizeof(MES_ONE); Mes_One->num = num; return write(out,(char*)Mes_One,Mes_One->base.size); } HMES_ONE ReadMes_ONE(int in,HMessage HMES) { HMES_ONE Mes_One = (HMES_ONE) malloc (sizeof(MES_ONE)); memcpy(Mes_One,HMES,sizeof(Message)); read(in,(char*)Mes_One + sizeof(Message),sizeof(MES_ONE) - sizeof(Message)); return Mes_One; } //消息 Type_2 size_t SendMes_TWO(int out,char* str) { HMES_TWO Mes_Two = (HMES_TWO) malloc (sizeof(MES_TWO) + strlen(str)); Mes_Two->base.msg_kind = Type_2; Mes_Two->base.size = sizeof(MES_TWO) + strlen(str); memcpy(Mes_Two->str,str,strlen(str) + 1); return write(out,(char*)Mes_Two,Mes_Two->base.size); } HMES_TWO ReadMes_TWO(int in,HMessage HMES) { HMES_TWO Mes_Two = (HMES_TWO) malloc (HMES->size); memcpy(Mes_Two,HMES,sizeof(Message)); read(in,Mes_Two->str,HMES->size - sizeof(Message)); return Mes_Two; } //消息 Type_3 size_t SendMes_THREE(int out,int num,char* str) { HMES_THREE Mes_Three = (HMES_THREE) malloc (sizeof(MES_THREE) + strlen(str)); Mes_Three->base.msg_kind = Type_3; Mes_Three->base.size = sizeof(MES_THREE) + strlen(str); Mes_Three->num = num; memcpy(Mes_Three->str,str,strlen(str) + 1); return write(out,(char *)Mes_Three,Mes_Three->base.size); } HMES_THREE ReadMes_THREE(int in,HMessage HMES) { HMES_THREE Mes_Three = (HMES_THREE) malloc (HMES->size); memcpy(Mes_Three,HMES,sizeof(Message)); read(in,(char*)Mes_Three + sizeof(Message),sizeof(MES_THREE) - sizeof(Message)); return Mes_Three; }

**运行截图:**

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[Center]: /images/20220603/29ac0ff7645848899f134ebb36faaf97.png