1. Password should start with a capital (uppercase) letter
2. Password should contain a lower-case letter
3. Password should contain a number
4. Password length should be a minimum of 8 and less than 16 characters

I want to use POSIX character classes in a bash script and I have following (it doesn't work). I don't know how to group so that I can meet the length condition.

^[[:upper:]][[:lower:]]+[[:upper:]]*[[:digit:]]+$ Where should {8,15} go?