pfds              826 user/usertests.c   int pfds[2];
pfds              846 user/usertests.c   pipe(pfds);
pfds              853 user/usertests.c     close(pfds[0]);
pfds              854 user/usertests.c     if(write(pfds[1], "x", 1) != 1)
pfds              856 user/usertests.c     close(pfds[1]);
pfds              861 user/usertests.c   close(pfds[1]);
pfds              862 user/usertests.c   if(read(pfds[0], buf, sizeof(buf)) != 1){
pfds              866 user/usertests.c   close(pfds[0]);