lib/libc/string/strtok.c

   1 /*-
   2  * Copyright (c) 1998 Softweyr LLC.  All rights reserved.
   3  *
   4  * strtok_r, from Berkeley strtok
   5  * Oct 13, 1998 by Wes Peters <wes@softweyr.com>
   6  *
   7  * Copyright (c) 1988, 1993
   8  *      The Regents of the University of California.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notices, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notices, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  25  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE
  26  * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  28  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  29  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  * @(#)strtok.c 8.1 (Berkeley) 6/4/93
  35  * $FreeBSD: src/lib/libc/string/strtok.c,v 1.10 2007/12/12 18:33:06 wes Exp $
  36  * $DragonFly: src/lib/libc/string/strtok.c,v 1.3 2005/04/28 13:25:12 joerg Exp $
  37  */
  38
  39 #include <stddef.h>
  40 #ifdef DEBUG_STRTOK
  41 #include <stdio.h>
  42 #endif
  43 #include <string.h>
  44
  45 char    *__strtok_r(char *, const char *, char **);
  46
  47 __weak_reference(__strtok_r, strtok_r);
  48
  49 char *
  50 __strtok_r(char *s, const char *delim, char **last)
  51 {
  52         const char *spanp;
  53         int c, sc;
  54         char *tok;
  55
  56         if (s == NULL && (s = *last) == NULL)
  57                 return (NULL);
  58
  59         /*
  60          * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
  61          */
  62 cont:
  63         c = *s++;
  64         for (spanp = delim; (sc = *spanp++) != 0;) {
  65                 if (c == sc)
  66                         goto cont;
  67         }
  68
  69         if (c == 0) {           /* no non-delimiter characters */
  70                 *last = NULL;
  71                 return (NULL);
  72         }
  73         tok = s - 1;
  74
  75         /*
  76          * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
  77          * Note that delim must have one NUL; we stop if we see that, too.
  78          */
  79         for (;;) {
  80                 c = *s++;
  81                 spanp = delim;
  82                 do {
  83                         if ((sc = *spanp++) == c) {
  84                                 if (c == 0)
  85                                         s = NULL;
  86                                 else
  87                                         s[-1] = '\0';
  88                                 *last = s;
  89                                 return (tok);
  90                         }
  91                 } while (sc != 0);
  92         }
  93         /* NOTREACHED */
  94 }
  95
  96 char *
  97 strtok(char *s, const char *delim)
  98 {
  99         static char *last;
 100
 101         return (__strtok_r(s, delim, &last));
 102 }
 103
 104 #ifdef DEBUG_STRTOK
 105 /*
 106  * Test the tokenizer.
 107  */
 108 int
 109 main(void)
 110 {
 111         char blah[80], test[80];
 112         char *brkb, *brkt, *phrase, *sep, *word;
 113
 114         sep = "\\/:;=-";
 115         phrase = "foo";
 116
 117         printf("String tokenizer test:\n");
 118         strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
 119         for (word = strtok(test, sep); word; word = strtok(NULL, sep))
 120                 printf("Next word is \"%s\".\n", word);
 121         strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
 122
 123         for (word = strtok_r(test, sep, &brkt); word;
 124             word = strtok_r(NULL, sep, &brkt)) {
 125                 strcpy(blah, "blah:blat:blab:blag");
 126
 127                 for (phrase = strtok_r(blah, sep, &brkb); phrase;
 128                     phrase = strtok_r(NULL, sep, &brkb))
 129                         printf("So far we're at %s:%s\n", word, phrase);
 130         }
 131
 132         return (0);
 133 }
 134
 135 #endif /* DEBUG_STRTOK */