usr/src/cmd/sgs/tsort/common/errstrtok.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22
  23 /*
  24  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  25  * Use is subject to license terms.
  26  */
  27
  28 /*      Copyright (c) 1988 AT&T */
  29 /*        All Rights Reserved   */
  30
  31
  32 #pragma ident   "%Z%%M% %I%     %E% SMI"
  33
  34 /*
  35  *      This is exactly strtok(3C).
  36  *      It is here, with a different name, because using strtok() within
  37  *      the scope of errverb() can cause the loss of a currently remembered
  38  *      string(savept).
  39  */
  40
  41 /*
  42  * uses strpbrk and strspn to break string into tokens on
  43  * sequentially subsequent calls.  returns NULL when no
  44  * non-separator characters remain.
  45  * `subsequent' calls are calls with first argument NULL.
  46  */
  47
  48 #include <string.h>
  49
  50 char *
  51 errstrtok(char *string, char *sepset)
  52 {
  53         char    *p, *q, *r;
  54         static char     *savept;
  55
  56         /* first or subsequent call */
  57         p = (string == NULL)? savept: string;
  58
  59         if (p == 0)             /* return if no tokens remaining */
  60                 return (NULL);
  61
  62         q = p + strspn(p, sepset);      /* skip leading separators */
  63
  64         if (*q == '\0')         /* return if no tokens remaining */
  65                 return (NULL);
  66
  67         if ((r = strpbrk(q, sepset)) == NULL)   /* move past token */
  68                 savept = 0;     /* indicate this is last token */
  69         else {
  70                 *r = '\0';
  71                 savept = ++r;
  72         }
  73         return (q);
  74 }