glibc/string/strtok.c

/* Copyright (C) 1991,1996,1997,1999,2000,2001,2007
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <string.h>


static char *olds;

#undef strtok

/* Parse S into tokens separated by characters in DELIM.
   If S is NULL, the last string strtok() was called with is
   used.  For example:
	char s[] = "-abc-=-def";
	x = strtok(s, "-");		// x = "abc"
	x = strtok(NULL, "-=");		// x = "def"
	x = strtok(NULL, "=");		// x = NULL
		// s = "abc\0=-def\0"
*/
char *
strtok (s, delim)
     char *s;
     const char *delim;
{
  char *token;

  if (s == NULL)
    s = olds;

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

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