writeopen          19 pipe.c           int writeopen;  // write fd is still open
writeopen          34 pipe.c           p->writeopen = 1;
writeopen          64 pipe.c             p->writeopen = 0;
writeopen          70 pipe.c           if(p->readopen == 0 && p->writeopen == 0){
writeopen         106 pipe.c           while(p->nread == p->nwrite && p->writeopen){  //DOC: pipe-empty