共有メモリによるプロセス間通信の実現

#include "sys/types.h"
#include 
#include "unistd.h"
#include "stdio.h"
#include "stdlib.h"
#include "sys/shm.h"
#include "string.h"

struct mybuf{
        int pid;
        char buf[128];
};
void fun(int sigunm){

        return;

}
int main(){

        int shmid;
        struct mybuf * p;
        int pid;
        int key;
         key=ftok("./a.c",'a');
        if(key<0){
                printf("create key failure
");
                return -1;
        }
        printf("create key success");

        shmid=shmget(key,128,IPC_CREAT|0777);//      

        if(shmid<0){
                printf("create share memory failure
");
                return -1;
        }
        printf("create share memory success shime=%d
",shmid);

        signal(SIGUSR1,fun);//      SIGUSER2
        p=(struct mybuf * )shmat(shmid,NULL,0);//            
        if(p==NULL){
                printf("shmat function failure
");
                return -3;
        }
        //     pid
        p->pid=getpid();
        pause();//   client read server pid;
        pid=p->pid;

        while(1){
                printf("parent process start write share memory:
");
                fgets(p->buf,128,stdin);//         
                kill(pid,SIGUSR2);//  SIGUSER1     client pid
                printf("send SIGUSR2 pid=%d, buf=%s",pid,p->buf);
                pause();//     
        }


        shmdt(p);
        shmctl(shmid,IPC_RMID,NULL);
        system("ipcs -m ");
        return 0;
}

#include "sys/types.h"
#include 
#include "unistd.h"
#include "stdio.h"
#include "stdlib.h"
#include "sys/shm.h"
#include "string.h"

struct mybuf{
        int pid;
        char buf[128];
};
void fun(int sigunm){

        return;

}
int main(){

        int shmid;
        struct mybuf * p;
        int pid;
        int key;
        key=ftok("./a.c",'a');
        if(key<0){
                printf("create key failure
");
                return -1;
        }
        printf("create key success");

        shmid=shmget(key,128,IPC_CREAT|0777);//      

        if(shmid<0){
                printf("create share memory failure
");
                return -1;
        }
        printf("create share memory success shime=%d
",shmid);

        signal(SIGUSR2,fun);//      SIGUSER2
        p=(struct mybuf * )shmat(shmid,NULL,0);//            
        if(p==NULL){
                printf("shmat function failure
");
                return -3;
        }
        //  server  pid
        pid=p->pid;//read memory
        //write client pid to share memory
        p->pid=getpid();
        //kill signal
        kill(pid,SIGUSR1);
        printf("server pid=%d lient pid=%d",pid,p->pid);
        //clitent start read data from memery
        while(1){
                pause();//waite server write data
                printf("client process receve data:%s
 send to server pid=%d",p->buf,pid);
                kill(pid,SIGUSR1);//  SIGUSER1     server write memory
        }


        shmdt(p);
        shmctl(shmid,IPC_RMID,NULL);
        system("ipcs -m ");
        return 0;
}