/* * dup2.c * * Ersatz dup2() for really ancient systems */#include "config.h"int dup2(int oldfd, int newfd){  int rv, nfd;  close(newfd);  nfd = rv = dup(oldfd);  if (rv >= 0 && rv != newfd) {    rv = dup2(oldfd, newfd);    close(nfd);  }  return rv;}