c substring

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

void substring(char source[], int start, int count, char destination[]) {
    int i;
    for (i = 0; i < count && source[start + i] != '\0'; ++i) {
        destination[i] = source[start + i];
    }
    destination[i] = '\0';
}

int main() {
    char str[] = "This is a sample string";
    int start = 5;
    int count = 7;
    char sub[count + 1];

    substring(str, start, count, sub);
    printf("Substring: %s\n", sub);

    return 0;
}