dup-safer.c 1.2 KB

123456789101112131415161718192021222324252627282930313233343536373839404142
  1. /* Invoke dup, but avoid some glitches.
  2. Copyright (C) 2001, 2004, 2005, 2006, 2009 Free Software
  3. Foundation, Inc.
  4. This program is free software: you can redistribute it and/or modify
  5. it under the terms of the GNU General Public License as published by
  6. the Free Software Foundation; either version 3 of the License, or
  7. (at your option) any later version.
  8. This program is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11. GNU General Public License for more details.
  12. You should have received a copy of the GNU General Public License
  13. along with this program. If not, see <http://www.gnu.org/licenses/>. */
  14. /* Written by Paul Eggert. */
  15. #include <config.h>
  16. #include "unistd-safer.h"
  17. #include <fcntl.h>
  18. #include <unistd.h>
  19. /* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
  20. STDERR_FILENO. */
  21. int
  22. dup_safer (int fd)
  23. {
  24. #if defined F_DUPFD && !defined FCHDIR_REPLACEMENT
  25. return fcntl (fd, F_DUPFD, STDERR_FILENO + 1);
  26. #else
  27. /* fd_safer calls us back, but eventually the recursion unwinds and
  28. does the right thing. */
  29. return fd_safer (dup (fd));
  30. #endif
  31. }