errfd             696 user/usertests.c     int errfd = dup(1);
errfd             697 user/usertests.c     if (errfd < 0) {
errfd             704 user/usertests.c       fprintf(errfd, "%s: create failed\n", s);
errfd             708 user/usertests.c       fprintf(errfd, "%s: wrong fd\n", s);
errfd             712 user/usertests.c       fprintf(errfd, "%s: exec echo failed\n", s);