ppipe.c~

设有二元函数 f(x,y) = f(x) + f(y) 其中：f(x) = f(x-1) * x (x>1) f(x) = 1 (x=

/*
   * Filename     : ppipe.c
   * copyright : (C) 2009 by Leon
                : 利用管道实现在父子进程间传递整数
   * Function
 */
#include<stdlib.h>
#include<stdio.h>
#include<unistd.h>
int main(int argc,char *argv[])
{
     int pid1;
     int pid2;
     int pipe1[2];
     int pipe2[2];
     int pipe3[2];
     int pipe4[2];
     
     int fx;
     int fy1;
     int fy2;
     int fxy;
     int x;
     int y;
    int m;
    int n;
printf("请输入 x 和 y 的值。\n");
    scanf("%d",&m);
    scanf("%d",&n);
     
     if(pipe(pipe1)<0){
        perror("pipe not create");
        exit(EXIT_FAILURE);
                     }
     if(pipe(pipe2)<0){
        perror("pipe not create");
        exit(EXIT_FAILURE);
                     } 
     if(pipe(pipe3)<0){
        perror("pipe not create");
        exit(EXIT_FAILURE);
                      }
     if(pipe(pipe4)<0){
        perror("pipe not create");
        exit(EXIT_FAILURE);
                     }
     if((pid1=fork())<0){
        perror("pipe not create");
        exit(EXIT_FAILURE);
                   }
     else if(pid1==0){
        close(pipe1[1]);
        close(pipe2[0]);
       do{
        read(pipe1[0],&x,sizeof(int));
        printf("child %d read:%d\n",getpid(),x);
        read(pipe1[0],&fx,sizeof(int));
        printf("child %d read:%d\n",getpid,fx);
        fx=fx*x;
        write(pipe2[1],&fx,sizeof(int));
                  }while(x<m);
        close(pipe1[0]);
        close(pipe2[1]);
        exit(EXIT_SUCCESS);
                     } 
      else if ((pid2=fork())<0)
                 {
        perror("process not create");
        exit(EXIT_FAILURE);
           }
      else if(pid2==0)
        {
        close(pipe3[1]);
        close(pipe4[0]);
int s=2;
  do{
     read(pipe3[0],&fy1,sizeof(int));
     printf("child %d read: %d\n",getpid(),fy1);
     read(pipe3[0],&fy2,sizeof(int));
     printf("child %d read: %d\n",getpid(),fy2);
     fy1=fy1+fy2;
     write(pipe4[1],&fy1,sizeof(int));
s++;
    }while(s<n);
close(pipe3[0]);
close(pipe4[1]);
exit(EXIT_SUCCESS);
}
else
{
close(pipe3[0]);
close(pipe4[1]);
close(pipe1[0]);
close(pipe2[1]);
y=2;
fy1=1;
fy2=1;
x=1;
fx=1;

   while(x<m){
    x++;
  write(pipe1[1],&x,sizeof(int));
  printf("parent %d write:%d\n",getpid(),x);
  write(pipe1[1],&fx,sizeof(int));
  printf("parent %d write:%d\n",getpid(),fx);
  read(pipe2[0],&fx,sizeof(int));
}
   

while(y<n){
  write(pipe3[1],&fy1,sizeof(int));
  printf("parent %d read:%d\n",getpid(),fy1);
  write(pipe3[1],&fy2,sizeof(int));
  printf("parent %d read:%d\n",getpid(),fy2);
  fy1=fy2;
  read(pipe4[0],&fy2,sizeof(int));
y++;
}


close(pipe1[1]);
close(pipe2[0]);
close(pipe3[1]);
close(pipe4[0]);


printf("the result is :%d",fx+fy2);
return EXIT_SUCCESS;
}
}