1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <string.h>
      19  
      20  #undef strncpy
      21  
      22  #ifndef STRNCPY
      23   #define STRNCPY strncpy
      24  #endif
      25  
      26  char *
      27  STRNCPY (char *s1, const char *s2, size_t n)
      28  {
      29    size_t size = __strnlen (s2, n);
      30    if (size != n)
      31      memset (s1 + size, '\0', n - size);
      32    return memcpy (s1, s2, size);
      33  }
      34  libc_hidden_builtin_def (strncpy)