tmpnam.c 1.8 KB

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  1. /* Copyright (C) 1991, 1993, 1996, 1997, 1998 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Library General Public License as
  5. published by the Free Software Foundation; either version 2 of the
  6. License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Library General Public License for more details.
  11. You should have received a copy of the GNU Library General Public
  12. License along with the GNU C Library; see the file COPYING.LIB. If not,
  13. write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14. Boston, MA 02111-1307, USA. */
  15. #include <stdio.h>
  16. #include <string.h>
  17. extern int __path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
  18. int try_tmpdir);
  19. extern int __gen_tempname (char *tmpl, int openit);
  20. static char tmpnam_buffer[L_tmpnam];
  21. /* Generate a unique filename in P_tmpdir.
  22. This function is *not* thread safe when S == NULL! */
  23. char * tmpnam (char *s)
  24. {
  25. /* By using two buffers we manage to be thread safe in the case
  26. where S != NULL. */
  27. char tmpbuf[L_tmpnam];
  28. /* In the following call we use the buffer pointed to by S if
  29. non-NULL although we don't know the size. But we limit the size
  30. to L_tmpnam characters in any case. */
  31. if (__path_search (s ? : tmpbuf, L_tmpnam, NULL, NULL, 0))
  32. return NULL;
  33. if (__gen_tempname (s ? : tmpbuf, 0))
  34. return NULL;
  35. if (s == NULL)
  36. return (char *) memcpy (tmpnam_buffer, tmpbuf, L_tmpnam);
  37. return s;
  38. }