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

int main ()
{
    const char * read_only = "monkey";
    char * duplicate;
    char * three_dup;
    duplicate = strdup (read_only);
    /* We can write to this string. */
    duplicate[0] = toupper (duplicate[0]);
    printf ("%s -> %s\n", read_only, duplicate);
    /* Now copy three characters. */
    three_dup = strndup (read_only, 3);
    /* It actually allocates four bytes, since a trailing 0 is added. */
    printf ("%s -> %s\n", read_only, three_dup);
    /* We need to free it when the program finishes. */
    free (duplicate);
    free (three_dup);
    return 0;
}