/* Duplicate an open file descriptor to a specified file descriptor. Copyright 1999 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* written by Paul Eggert */ #if HAVE_CONFIG_H # include #endif #include #ifndef errno extern int errno; #endif #if HAVE_FCNTL_H # include #endif #if HAVE_UNISTD_H # include #endif #ifndef F_DUPFD static int dupfd (int fd, int desired_fd) { int duplicated_fd = dup (fd); if (duplicated_fd < 0 || duplicated_fd == desired_fd) return duplicated_fd; else { int r = dupfd (fd, desired_fd); int e = errno; close (duplicated_fd); errno = e; return r; } } #endif int dup2 (int fd, int desired_fd) { if (fd == desired_fd) return fd; close (desired_fd); #ifdef F_DUPFD return fcntl (fd, F_DUPFD, desired_fd); #else return dupfd (fd, desired_fd); #endif }