C, strtok

Hello /prog/

Could anyone help me with using the C function strtok and strtok_r?

I've read the man pages and it doesn't provide much help. Try compiling this code example gotten from the man pages:

http://pastebin.com/d11d44ccf

Here's a "MADNESS LIES HERE" version I wrote when I was bored a year ago:


toknobj.h:

#ifndef _TOKNOBJ_H_
#define _TOKNOBJ_H_

#define OOPINVOKEBASE(obj,type,method) ((C##type##VTable*)(##obj->VTable))->##method(##obj)
#define OOPINVOKEBASEVAR(obj,type,method) ((C##type##VTable*)(##obj->VTable))->##method(##obj,##args)
#define OOPDESTRUCT(obj,type) ((C##type##VTable*)(##obj->VTable))->Destroy##type(##obj);obj=NULL;

typedef struct _TokenObject
{
        const void *VTable;

        char *separators; // public read-only
        char *string; // public mutable
        char *current; // pointer to current token in string, private mutable
        char *last; // pointer to end-of-string, private read-only
} TokenObject;

void DestroyTokenObject(TokenObject *to);
char *GetToken(TokenObject *to);
TokenObject *CreateTokenObject(char *s, char *seps);

typedef struct _CTokenObjectVTable
{
        void ( * DestroyTokenObject)(TokenObject*) ;
        char* ( * GetToken)(TokenObject*);
} CTokenObjectVTable;


#endif

toknobj.c:

#include <stdlib.h>
#include "toknobj.h"

const CTokenObjectVTable TokenObjectVTable = { DestroyTokenObject, GetToken };

TokenObject *CreateTokenObject(char *s, char *seps)
{
        TokenObject *to;

        to = (TokenObject*)malloc(sizeof(TokenObject));
        to->separators = (char*)strdup(seps);
        to->string = (char*)strdup(s);
        to->current = to->string;
        to->last = (to->string)+strlen(s);
        to->VTable = &TokenObjectVTable;

        return to;
}

void DestroyTokenObject(TokenObject *to)
{
        free(to->separators);
        free(to->string);
        free(to);
}

char *GetToken(TokenObject *to)
{
        char *s;
        char *end;
        char *last;
        char *seps;

        s = to->current;
        seps = to->separators;
        last = to->last;

        if (last <= s ) return NULL;

        for(;*s&&strrchr(seps,*s);s++); // skip separators at the beginning of the token

        if (last <= s ) return NULL;

        for(end=s;*end&&!strrchr(seps,*end);end++);
        if(*end) *end=0;
        end++;
       
        to->current = end;

        return s;

}


// Usage is like this (copy pasted from some real code I wrote, I'm too lazy to write a real example):

char *GetMkvSplitString(char *cutlist, int *splitcount, FRAMERATE *fr)
{
        char *tok;
        char *splits;
        int parity = 0;

        TokenObject *to = CreateTokenObject(cutlist,",");
        splits = calloc(1,1);

        while (tok = OOPINVOKEBASE(to,TokenObject,GetToken))
        {
                int frame = atoi(tok)+parity;
                if (frame)
                {
                        ReallocStrCat(&splits,GetTimeStrFromFrames(frame,fr));
                        ReallocStrCat(&splits,",");
                        (*splitcount)++;
                }
                parity = parity?0:1;
        }

        OOPDESTRUCT(to,TokenObject);
        splits[strlen(splits)-1]=0; // clear last ,

        return splits;
}

// Irrelevant, but in case you're wondering, inn util.c:
char *ReallocStrCat( char *dst[], char src[] ) // outputs new pointer to *dst
{
        char *newstr;

        newstr = malloc(strlen(*dst)+strlen(src)+1);
        strcpy(newstr,*dst);
        strcat(newstr,src);

        free(*dst);

        *dst = newstr;
        return newstr;
}