stpncpy.c 1.4 KB

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  1. /* Copyright (C) 1993-2026 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 Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the 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. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, see
  13. <https://www.gnu.org/licenses/>. */
  14. #ifdef HAVE_CONFIG_H
  15. # include <config.h>
  16. #endif
  17. #ifdef _LIBC
  18. # include <string.h>
  19. #else
  20. # include <sys/types.h>
  21. #endif
  22. #ifndef STPNCPY
  23. # ifdef weak_alias
  24. # define STPNCPY __stpncpy
  25. weak_alias (__stpncpy, stpncpy)
  26. # else
  27. # define STPNCPY stpncpy
  28. # endif
  29. #endif
  30. /* Copy no more than N characters of SRC to DEST, returning the address of
  31. the terminating '\0' in DEST, if any, or else DEST + N. */
  32. char *
  33. STPNCPY (char *dest, const char *src, size_t n)
  34. {
  35. size_t size = __strnlen (src, n);
  36. memcpy (dest, src, size);
  37. dest += size;
  38. if (size == n)
  39. return dest;
  40. return memset (dest, '\0', n - size);
  41. }
  42. #ifdef weak_alias
  43. libc_hidden_def (__stpncpy)
  44. #endif