sysdeps/generic/strtok_r.c

   1 /* Reentrant string tokenizer.  Generic version.
   2    Copyright (C) 1991, 1996, 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <string.h>
  21
  22 #undef strtok_r
  23 #undef __strtok_r
  24
  25 /* Parse S into tokens separated by characters in DELIM.
  26    If S is NULL, the saved pointer in SAVE_PTR is used as
  27    the next starting point.  For example:
  28         char s[] = "-abc-=-def";
  29         char *sp;
  30         x = strtok_r(s, "-", &sp);      // x = "abc", sp = "=-def"
  31         x = strtok_r(NULL, "-=", &sp);  // x = "def", sp = NULL
  32         x = strtok_r(NULL, "=", &sp);   // x = NULL
  33                 // s = "abc\0-def\0"
  34 */
  35 char *
  36 __strtok_r (s, delim, save_ptr)
  37      char *s;
  38      const char *delim;
  39      char **save_ptr;
  40 {
  41   char *token;
  42
  43   if (s == NULL)
  44     s = *save_ptr;
  45
  46   /* Scan leading delimiters.  */
  47   s += strspn (s, delim);
  48   if (*s == '\0')
  49     {
  50       *save_ptr = s;
  51       return NULL;
  52     }
  53
  54   /* Find the end of the token.  */
  55   token = s;
  56   s = strpbrk (token, delim);
  57   if (s == NULL)
  58     /* This token finishes the string.  */
  59     *save_ptr = __rawmemchr (token, '\0');
  60   else
  61     {
  62       /* Terminate the token and make *SAVE_PTR point past it.  */
  63       *s = '\0';
  64       *save_ptr = s + 1;
  65     }
  66   return token;
  67 }
  68 weak_alias (__strtok_r, strtok_r)