#include <unistd.h>
int my_strlen(const char *str) {
    int len = 0;
    while (str[len] != '\0') {
        len++;
    }
    return len;
}

void my_strcpy(char *dest, const char *src) {
    int i = 0;
    while (src[i] != '\0') {
        dest[i] = src[i];
        i++;
    }
    dest[i] = '\0';
}

int main() {
    // Declare an empty string with a fixed size
char string[100] = "";

    // Populate the string with a value later
my_strcpy(string, "Hello, world!");

    // Print the string
write(1, string, my_strlen(string));
    write(1, "\n", 1);

    return 0;
}