lib/xmemdup0.c

   1 /* xmemdup0.c -- copy a block of arbitrary bytes, plus a trailing NUL
   2
   3    Copyright (C) 2008-2024 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 #include "xmemdup0.h"
  21 #include "xalloc.h"
  22
  23 #include <string.h>
  24
  25 /* Clone an arbitrary block of bytes P of size S, with error checking,
  26    and include a terminating NUL byte.  P is of type 'void const *',
  27    to make it easier to use this with other mem* functions that return
  28    'void *', but since appending a NUL byte only makes sense on bytes,
  29    the return type is 'char *'.
  30
  31    The terminating NUL makes it safe to use strlen or rawmemchr to
  32    check for embedded NUL; it also speeds up algorithms such as escape
  33    sequence processing on arbitrary memory, by making it always safe
  34    to read the byte after the escape character rather than having to
  35    check if each escape character is the last byte in the object.  */
  36
  37 char *
  38 xmemdup0 (void const *p, size_t s)
  39 {
  40   char *result = xcharalloc (s + 1);
  41   if (s > 0)
  42     memcpy (result, p, s);
  43   result[s] = 0;
  44   return result;
  45 }