C string tokenizer that returns empty strings for adjacent delimiters

tokenize.c

/* TOKENIZE -- demonstrates a way to tokenize a string, with adjacent delimiters
 * returned as empty strings. 
 * Partially based on: http://stackoverflow.com/questions/874161
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

/* Function declarations */
unsigned int tokenize(const char* text, char delim, char*** output);
void reclaim2D(char ***store, unsigned int itemCount);

int main(void) {

	/* Tokenizer test */
	char* string1 = "ABC,DE,F";
	char* string2 = "AB,C,DEF,G,";
	char* string3 = ",";
	char* string4 = "";
	char* string5 = ",,A,,";
	char* string6 = ",ABC,";

	unsigned int i,c;
	char** tokens = NULL;

	printf("string1: '%s'\n", string1);
	c=tokenize(string1,',',&tokens);
	for(i=0;i<c;i++) {
		printf("\ttoken %d: '%s'\n",i+1,tokens[i]);
	}
	reclaim2D(&tokens, c);

	printf("string2: '%s'\n", string2);
	c=tokenize(string2,',',&tokens);
	for(i=0;i<c;i++) {
		printf("\ttoken %d: '%s'\n",i+1,tokens[i]);
	}
	reclaim2D(&tokens, c);

	printf("string3: '%s'\n", string3);
	c=tokenize(string3,',',&tokens);
	for(i=0;i<c;i++) {
		printf("\ttoken %d: '%s'\n",i+1,tokens[i]);
	}
	reclaim2D(&tokens, c);

	printf("string4: '%s'\n", string4);
	c=tokenize(string4,',',&tokens);
	for(i=0;i<c;i++) {
		printf("\ttoken %d: '%s'\n",i+1,tokens[i]);
	}
	reclaim2D(&tokens, c);

	printf("string5: '%s'\n", string5);
	c=tokenize(string5,',',&tokens);
	for(i=0;i<c;i++) {
		printf("\ttoken %d: '%s'\n",i+1,tokens[i]);
	}
	reclaim2D(&tokens, c);

	printf("string6: '%s'\n", string6);
	c=tokenize(string6,',',&tokens);
	for(i=0;i<c;i++) {
		printf("\ttoken %d: '%s'\n",i+1,tokens[i]);
	}
	reclaim2D(&tokens, c);
	return 0;
}

unsigned int tokenize(const char* text, char delim, char*** output) {
	if((*output) != NULL) return -1; /* I will allocate my own storage */
	int ndelims,i,j,ntokens,starttok,endtok;

	// First pass, count the number of delims
	i=0;
	ndelims=0;
	while(text[i] != '\0') {
		if(text[i] == delim) ndelims++;
		i++;
	}

	// The number of delims is one less than the number of tokens
	ntokens=ndelims+1;

	// Now, allocate an array of (char*)'s equal to the number of tokens

	(*output) = (char**) malloc(sizeof(char*)*ntokens);

	// Now, loop through and extract each token
	starttok=0;
	endtok=0;
	i=0;
	j=0;
	while(text[i] != '\0') {
		// Reached the end of a token?
		if(text[i] == delim) {
			endtok = i;
			// Allocate a char array to hold the token
			(*output)[j] = (char*) malloc(sizeof(char)*(endtok-starttok+1));
			// If the token is not empty, copy over the token
			if(endtok-starttok > 0)
				memcpy((*output)[j],&text[starttok],(endtok-starttok));
			// Null-terminate the string
			(*output)[j][(endtok-starttok)] = '\0';
			// The next token starts at i+1
			starttok = i+1;
			j++;
		}
		i++;
	}

	// Deal with the last token
	endtok = i;
	// Allocate a char array to hold the token
	(*output)[j] = (char*) malloc(sizeof(char)*(endtok-starttok+1));
	// If the token is not empty, copy over the token
	if(endtok-starttok > 0)
		memcpy((*output)[j],&text[starttok],(endtok-starttok));
	// Null-terminate the string
	(*output)[j][(endtok-starttok)] = '\0';
	
	return ntokens;

}

void reclaim2D(char ***store, unsigned int itemCount)
{
	int x;
    for (x = 0; x < itemCount; ++x)
    {
        if((*store)[x] != NULL) free((*store)[x]);
        (*store)[x] = NULL;
    }

    if((*store) != NULL) free((*store));
    (*store) = NULL;
}