usr/src/lib/libc/port/gen/strtok_r.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include "lint.h"
  33 #include <string.h>
  34 #include <stddef.h>
  35 #include <sys/types.h>
  36
  37 /*
  38  * uses strpbrk and strspn to break string into tokens on
  39  * sequentially subsequent calls.  returns NULL when no
  40  * non-separator characters remain.
  41  * `subsequent' calls are calls with first argument NULL.
  42  */
  43 char *
  44 strtok_r(char *string, const char *sepset, char **lasts)
  45 {
  46         char    *q, *r;
  47
  48         /* first or subsequent call */
  49         if (string == NULL)
  50                 string = *lasts;
  51
  52         if (string == NULL)             /* return if no tokens remaining */
  53                 return (NULL);
  54
  55         q = string + strspn(string, sepset);    /* skip leading separators */
  56
  57         if (*q == '\0')         /* return if no tokens remaining */
  58                 return (NULL);
  59
  60         if ((r = strpbrk(q, sepset)) == NULL)   /* move past token */
  61                 *lasts = NULL;  /* indicate this is last token */
  62         else {
  63                 *r = '\0';
  64                 *lasts = r + 1;
  65         }
  66         return (q);
  67 }