update from main archive 961005

[thirdparty/glibc.git] / sysdeps / generic / strtok_r.c

/* Reentrant string tokenizer.  Generic version.
Copyright (C) 1991, 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.

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

#include <string.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 = NULL
	x = strtok_r(NULL, "=", &sp);	// x = NULL
		// s = "abc\0-def\0"
*/
char *
strtok_r (s, delim, save_ptr)
     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')
    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;
}