sysdeps/generic/strtok_r.c

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