'-i' option for 'cp' and 'mv'

[Philip Cheng]

I am using a system running System V on a 386 machine.  In 4.3 bsd, 'cp'
and 'mv' have the option '-i' which will warn me if the file exists. 
In the system I am using, only 'rm' has such an option.   I would like to change
it so that '-i' will work for 'cp' and 'mv' as well.  Can someone tell me how to
do it?

Many thanks

philip