Printed string of length 3 to buffer of size 4 with snprintf.
Return value = 3
Buffer was null-terminated by snprintf

Printed string of length 4 to buffer of size 4 with snprintf.
Return value = 4
Buffer was NOT null-terminated by snprintf

Printed string of length 5 to buffer of size 4 with snprintf.
Return value = -1
Buffer was NOT null-terminated by snprintf