#include <stdio.h>
int main()
{
    int pid=_fork();
    FILE *f=fopen("~testpipe","rw");

    setvbuf(f,NULL,_IONBF,0);

    if(pid==0)
    {
	char buf[2];
	fread(f,buf,1,1);
	printf("[%c]\n",buf[0]);
    }
    else
    {
	char buf="666";
	fwrite(f,buf,1,1);
	printf("written\n");
    }
}