1  /* Implement the stpncpy function.
       2     Copyright (C) 2003-2023 Free Software Foundation, Inc.
       3     Written by Kaveh R. Ghazi <ghazi@caip.rutgers.edu>.
       4  
       5  This file is part of the libiberty library.
       6  Libiberty is free software; you can redistribute it and/or
       7  modify it under the terms of the GNU Library General Public
       8  License as published by the Free Software Foundation; either
       9  version 2 of the License, or (at your option) any later version.
      10  
      11  Libiberty is distributed in the hope that it will be useful,
      12  but WITHOUT ANY WARRANTY; without even the implied warranty of
      13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14  Library General Public License for more details.
      15  
      16  You should have received a copy of the GNU Library General Public
      17  License along with libiberty; see the file COPYING.LIB.  If
      18  not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
      19  Boston, MA 02110-1301, USA.  */
      20  
      21  /*
      22  
      23  @deftypefn Supplemental char* stpncpy (char *@var{dst}, const char *@var{src}, @
      24    size_t @var{len})
      25  
      26  Copies the string @var{src} into @var{dst}, copying exactly @var{len}
      27  and padding with zeros if necessary.  If @var{len} < strlen(@var{src})
      28  then return @var{dst} + @var{len}, otherwise returns @var{dst} +
      29  strlen(@var{src}).
      30  
      31  @end deftypefn
      32  
      33  */
      34  
      35  #include <ansidecl.h>
      36  #include <stddef.h>
      37  
      38  extern size_t strlen (const char *);
      39  extern char *strncpy (char *, const char *, size_t);
      40  
      41  char *
      42  stpncpy (char *dst, const char *src, size_t len)
      43  {
      44    size_t n = strlen (src);
      45    if (n > len)
      46      n = len;
      47    return strncpy (dst, src, len) + n;
      48  }