string tokenization in C with dynamic memory

tokenize.c

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

size_t tokenize(const char *s, const char *delim, char ***tokenarray)
{
    size_t size = 0, capacity = 4, wordlen;
    const char *begin = s, *end;
    char **tokens = malloc(capacity * sizeof(char *));
    
    do {
        begin += strspn(begin, delim);
        if(!*begin)
            break;
        end = strpbrk(begin, delim);
        wordlen = end ? (size_t)(end - begin) : strlen(begin);
        if(size == capacity) {
            capacity = capacity * 3 / 2;
            tokens = realloc(tokens, capacity * sizeof(char *));
        }
        memcpy(tokens[size] = malloc(wordlen + 1), begin, wordlen);
        tokens[size++][wordlen] = 0;
    } while((begin = end));
    *tokenarray = tokens;
    return size;
}

int main(void)
{
    const char *str = "The quick brown fox jumps over the lazy dog.\n";
    char **tokens;
    size_t numtok;

    numtok = tokenize(str, " .\n", &tokens);
    for(size_t i = 0; i < numtok; i++) {
        printf("got <%s>\n", tokens[i]);
    }
    
    for(size_t i = 0; i < numtok; i++) {
        free(tokens[i]);
    }
    free(tokens);
}

Thanks for this! Great modular function.