sysdeps/generic/strcat.c

   1 /* Copyright (C) 1991 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <string.h>
  21 #include <memcopy.h>
  22
  23 /* Append SRC on the end of DEST.  */
  24 char *
  25 DEFUN(strcat, (dest, src), char *dest AND CONST char *src)
  26 {
  27   register char *s1 = dest;
  28   register CONST char *s2 = src;
  29   reg_char c;
  30
  31   /* Find the end of the string.  */
  32   do
  33     c = *s1++;
  34   while (c != '\0');
  35
  36   /* Make S1 point before the next character, so we can increment
  37      it while memory is read (wins on pipelined cpus).  */
  38   s1 -= 2;
  39
  40   do
  41     {
  42       c = *s2++;
  43       *++s1 = c;
  44     }
  45   while (c != '\0');
  46
  47   return dest;
  48 }