Reply to thread

Message

[QUOTE="CBFalconer, post: 2468869"]
The following routine will do the extraction for you.  Try it first
with TESTING defined on compilation, and then without for your own
use.  With gcc you define it on the command line by: "gcc -DTESTING
toksplit.c"

/* ------- file toksplit.c ----------*/
#include "toksplit.h"

/* copy over the next token from an input string, after
   skipping leading blanks (or other whitespace?).  The
   token is terminated by the first appearance of tokchar,
   or by the end of the source string.

The caller must supply sufficient space in token to
   receive any token,  Otherwise tokens will be truncated.

Returns: a pointer past the terminating tokchar.

This will happily return an infinity of empty tokens if
   called with src pointing to the end of a string.  Tokens
   will never include a copy of tokchar.

A better name would be "strtkn", except that is reserved
   for the system namespace.  Change to that at your risk.

released to Public Domain, by C.B. Falconer.
   Published 2006-02-20.  Attribution appreciated.
*/

const char *toksplit(const char *src,      /* Source of tokens */
                     char tokchar,    /* token delimiting char */
                     char *token,  /* receiver of parsed token */
                     size_t lgh)   /* length token can receive */
                                   /* not including final '\0' */
{
   if (src) {
      while (' ' == *src) *src++;

while (*src && (tokchar != *src)) {
         if (lgh) {
            *token++ = *src;
            --lgh;
         }
         src++;
      }
      if (*src && (tokchar == *src)) src++;
   }
   *token = '\0';
   return src;
} /* toksplit */

#ifdef TESTING
#include <stdio.h>

#define ABRsize 6 /* length of acceptable token abbreviations */

int main(void)
{
   char teststring[] = "This is a test, ,,   abbrev, more";

const char *t, *s = teststring;
   int         i;
   char        token[ABRsize + 1];

puts(teststring);
   t = s;
   for (i = 0; i < 4; i++) {
      t = toksplit(t, ',', token, ABRsize);
      putchar(i + '1'); putchar(':');
      puts(token);
   }

puts("\nHow to detect 'no more tokens'");
   t = s; i = 0;
   while (*t) {
      t = toksplit(t, ',', token, 3);
      putchar(i + '1'); putchar(':');
      puts(token);
      i++;
   }

puts("\nUsing blanks as token delimiters");
   t = s; i = 0;
   while (*t) {
      t = toksplit(t, ' ', token, ABRsize);
      putchar(i + '1'); putchar(':');
      puts(token);
      i++;
   }
   return 0;
} /* main */

#endif
/* ------- end file toksplit.c ----------*/

/* ------- file toksplit.h ----------*/
#ifndef H_toksplit_h
#  define H_toksplit_h

#  ifdef __cplusplus
      extern "C" {
#  endif

#include <stddef.h>

/* copy over the next token from an input string, after
   skipping leading blanks (or other whitespace?).  The
   token is terminated by the first appearance of tokchar,
   or by the end of the source string.

The caller must supply sufficient space in token to
   receive any token,  Otherwise tokens will be truncated.

Returns: a pointer past the terminating tokchar.

+   This will happily return an infinity of empty tokens if
   called with src pointing to the end of a string.  Tokens
   will never include a copy of tokchar.

released to Public Domain, by C.B. Falconer.
   Published 2006-02-20.  Attribution appreciated.
*/

const char *toksplit(const char *src,      /* Source of tokens */
                     char tokchar,    /* token delimiting char */
                     char *token,  /* receiver of parsed token */
                     size_t lgh);  /* length token can receive */
                                   /* not including final '\0' */

#  ifdef __cplusplus
      }
#  endif
#endif
/* ------- end file toksplit.h ----------*/

-- 
Some useful references about C:
  <[URL]http://www.ungerhu.com/jxh/clc.welcome.txt[/URL]>
  <[URL]http://www.eskimo.com/~scs/C-faq/top.html[/URL]>
  <[URL]http://benpfaff.org/writings/clc/off-topic.html[/URL]>
  <[URL]http://anubis.dkuug.dk/jtc1/sc22/wg14/www/docs/n869/[/URL]> (C99)
  <[URL]http://www.dinkumware.com/refxc.html[/URL]>           (C-library}
  <[URL]http://gcc.gnu.org/onlinedocs/[/URL]>                  (GNU docs)
  <[URL]http://clc-wiki.net[/URL]>                               (C-info)
[/QUOTE]

Verification