string/swab.c

   1 /* Copyright (C) 1992, 1996, 1997 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <unistd.h>
  20
  21 void
  22 swab (const void *bfrom, void *bto, ssize_t n)
  23 {
  24   const char *from = (const char *) bfrom;
  25   char *to = (char *) bto;
  26
  27   n &= ~((ssize_t) 1);
  28   while (n > 1)
  29     {
  30       const char b0 = from[--n], b1 = from[--n];
  31       to[n] = b0;
  32       to[n + 1] = b1;
  33     }
  34 }