pipe管道通信阻塞

#include "public.h"

#define K 1024
#define WRITELEN (128*K)

int main()
{
 int result=-1;
 int fd[2],nbytes;
 pid_t pid;
 char string[WRITELEN]="你好，管道";
 char readbuffer[10*K];
 int *write_fd=&fd[1];
 int *read_fd=&fd[0];

 result=pipe(fd);
 if (-1==result)
 {
  printf("建立管道失败\n");
  return -1;
 }

 pid=fork();
 if (-1==pid)
 {
  printf("fork 进程失败\n");
  return -1;
 }
 if (0==pid)
 {
  int write_size=WRITELEN;
  result=0;

  close(*read_fd);
  while (write_size>=0)
  {
   result=write(*write_fd,string,write_size);
   if (result>0)
   {
    write_size-=result;
    printf("写入%d个数据，剩余%d个数据\n",result,write_size);
   }
   else
   {
    sleep(10);
   }
  }
  return 0;
 }
 else
 {
  close(*write_fd);

  while (1)
  {
   nbytes=read(*read_fd,readbuffer,sizeof(readbuffer));
   if (nbytes<=0)
   {
    printf("没有数据写入了\n");
    break;
   }
   printf("接受到%d个数据，内容为：%s\n",nbytes,readbuffer);
  }

 }
 

 return 0;
}

这就证明了管道的操作具有阻塞性质