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  *
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notices, this list of conditions and the following disclaimer.
  16  *
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notices, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *
  24  *      This product includes software developed by Softweyr LLC, the
  25  *      University of California, Berkeley, and its contributors.
  26  *
  27  * 4. Neither the name of the University nor the names of its contributors
  28  *    may be used to endorse or promote products derived from this software
  29  *    without specific prior written permission.
  30  *
  31  * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS
  32  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  34  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE
  35  * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  36  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  37  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  38  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  39  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  40  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  41  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  *
  43  * $FreeBSD: src/lib/libc/string/strtok.c,v 1.2.6.1 2001/07/09 23:30:07 obrien Exp $
  44  * $DragonFly: src/lib/libc/string/strtok.c,v 1.3 2005/04/28 13:25:12 joerg Exp $
  45  */
  46
  47 #include <stddef.h>
  48 #include <string.h>
  49
  50 char *
  51 strtok_r(char *s, const char *delim, char **last)
  52 {
  53     const char *spanp;
  54     int c, sc;
  55     char *tok;
  56
  57     if (s == NULL && (s = *last) == NULL)
  58     {
  59         return NULL;
  60     }
  61
  62     /*
  63      * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
  64      */
  65 cont:
  66     c = *s++;
  67     for (spanp = delim; (sc = *spanp++) != 0; )
  68     {
  69         if (c == sc)
  70         {
  71             goto cont;
  72         }
  73     }
  74
  75     if (c == 0)         /* no non-delimiter characters */
  76     {
  77         *last = NULL;
  78         return NULL;
  79     }
  80     tok = s - 1;
  81
  82     /*
  83      * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
  84      * Note that delim must have one NUL; we stop if we see that, too.
  85      */
  86     for (;;)
  87     {
  88         c = *s++;
  89         spanp = delim;
  90         do
  91         {
  92             if ((sc = *spanp++) == c)
  93             {
  94                 if (c == 0)
  95                 {
  96                     s = NULL;
  97                 }
  98                 else
  99                 {
 100                     char *w = s - 1;
 101                     *w = '\0';
 102                 }
 103                 *last = s;
 104                 return tok;
 105             }
 106         }
 107         while (sc != 0);
 108     }
 109     /* NOTREACHED */
 110 }
 111
 112
 113 char *
 114 strtok(char *s, const char *delim)
 115 {
 116     static char *last;
 117
 118     return strtok_r(s, delim, &last);
 119 }
 120
 121
 122 #if defined(DEBUG_STRTOK)
 123
 124 /*
 125  * Test the tokenizer.
 126  */
 127 int
 128 main()
 129 {
 130     char test[80], blah[80];
 131     char *sep = "\\/:;=-";
 132     char *word, *phrase, *brkt, *brkb;
 133
 134     printf("String tokenizer test:\n");
 135
 136     strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
 137
 138     for (word = strtok(test, sep);
 139          word;
 140          word = strtok(NULL, sep))
 141     {
 142         printf("Next word is \"%s\".\n", word);
 143     }
 144
 145     phrase = "foo";
 146
 147     strcpy(test, "This;is.a:test:of=the/string\\tokenizer-function.");
 148
 149     for (word = strtok_r(test, sep, &brkt);
 150          word;
 151          word = strtok_r(NULL, sep, &brkt))
 152     {
 153         strcpy(blah, "blah:blat:blab:blag");
 154
 155         for (phrase = strtok_r(blah, sep, &brkb);
 156              phrase;
 157              phrase = strtok_r(NULL, sep, &brkb))
 158         {
 159             printf("So far we're at %s:%s\n", word, phrase);
 160         }
 161     }
 162
 163     return 0;
 164 }
 165
 166 #endif /* DEBUG_STRTOK */