newlib/libc/string/strtok_r.c

   1 /*
   2  * Copyright (c) 1988 Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <string.h>
  31
  32 char *
  33 __strtok_r (register char *s,
  34         register const char *delim,
  35         char **lasts,
  36         int skip_leading_delim)
  37 {
  38         register char *spanp;
  39         register int c, sc;
  40         char *tok;
  41
  42
  43         if (s == NULL && (s = *lasts) == NULL)
  44                 return (NULL);
  45
  46         /*
  47          * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
  48          */
  49 cont:
  50         c = *s++;
  51         for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
  52                 if (c == sc) {
  53                         if (skip_leading_delim) {
  54                                 goto cont;
  55                         }
  56                         else {
  57                                 *lasts = s;
  58                                 s[-1] = 0;
  59                                 return (s - 1);
  60                         }
  61                 }
  62         }
  63
  64         if (c == 0) {           /* no non-delimiter characters */
  65                 *lasts = NULL;
  66                 return (NULL);
  67         }
  68         tok = s - 1;
  69
  70         /*
  71          * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
  72          * Note that delim must have one NUL; we stop if we see that, too.
  73          */
  74         for (;;) {
  75                 c = *s++;
  76                 spanp = (char *)delim;
  77                 do {
  78                         if ((sc = *spanp++) == c) {
  79                                 if (c == 0)
  80                                         s = NULL;
  81                                 else
  82                                         s[-1] = 0;
  83                                 *lasts = s;
  84                                 return (tok);
  85                         }
  86                 } while (sc != 0);
  87         }
  88         /* NOTREACHED */
  89 }
  90
  91 char *
  92 strtok_r (register char *__restrict s,
  93         register const char *__restrict delim,
  94         char **__restrict lasts)
  95 {
  96         return __strtok_r (s, delim, lasts, 1);
  97 }