dynamic string input with realloc

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

int main(void) {

    char* s = NULL; /* start off with just a pointer */
    size_t s_len = 0; /* A pointer to nothing has a strlen of 0. */

/*
    Start taking input, dynamically.
*/
    printf("Input a string...\n");

    do {

        s = realloc( s , ++s_len * sizeof(char) );

    } while ( ( s[ s_len - 1 ] = getchar() ) != '\n' );

    s[--s_len] = 0x00; /* remember to delimit the string! */
/*
    End dynamic input procedure.
*/

    printf("\n\n%s\n", s);
    printf("s_len = %i\n", (int)s_len);

    /* Print out the ASCII codes. */
    for (size_t i = 0; i < s_len; i++)
        printf("%i ", (int)s[i]);
    printf("\n");

    /* can't forget to free! */
    free(s);

}