C memset - elegantly add a null terminator

Question

I followed How to memset char array with null terminating character? to add a null terminator when using the C memset api.

The code worked; I no longer got odd in-memory chars added to the end of my malloc'd char array, due to the null terminator.

/* memset does not add a null terminator */
static void yd_vanilla_stars(size_t *number_of_chars, char *chars_to_pad)
{
    memset(chars_to_pad, 0, *number_of_chars+1);
    memset(chars_to_pad,'*',*number_of_chars);
}

Is there a more elegant way of achieving the same?

Answer 1

The question suggests that chars_to_pad points to memory allocated using malloc(). Another alternative is to use calloc() instead. This function automatically zero-initializes the allocated memory, so there is no need to zero the allocation in a separate step.

An example might look like this:

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

int main(void)
{
    size_t arr_sz = 11;
    char *arr = calloc(arr_sz, sizeof *arr);
    memset(arr, '*', arr_sz - 1);

    puts(arr);

    return 0;
}

Program output:

**********