strtok_r.c

/* Reentrant string tokenizer.  Generic version (Gnulib).
   Copyright (C) 1991, 1996-1999, 2001, 2004, 2007, 2009-2011 Free Software
   Foundation, Inc.
   This file is part of the GNU C Library.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <string.h>

#include "strtok_r.h"

/* Parse S into tokens separated by characters in DELIM.
   If S is NULL, the saved pointer in SAVE_PTR is used as
   the next starting point.  For example:
        char s[] = "-abc-=-def";
        char *sp;
        x = strtok_r(s, "-", &sp);      // x = "abc", sp = "=-def"
        x = strtok_r(NULL, "-=", &sp);  // x = "def", sp = ""
        x = strtok_r(NULL, "=", &sp);   // x = NULL,  sp = ""
                // s = "abc\0-def\0"
*/
char *
_mini_strtok_r (char *s, const char *delim, char **save_ptr)
{
  char *token;

  if (s == NULL)
    s = *save_ptr;

  /* Scan leading delimiters.  */
  s += strspn (s, delim);
  if (*s == '\0')
    {
      *save_ptr = s;
      return NULL;
    }

  /* Find the end of the token.  */
  token = s;
  s = strpbrk (token, delim);
  if (s == NULL)
    /* This token finishes the string.  */
    *save_ptr = strchr (token, '\0');
  else
    {
      /* Terminate the token and make *SAVE_PTR point past it.  */
      *s = '\0';
      *save_ptr = s + 1;
    }
  return token;
}