In scriptA.pl, there is use DBI
scriptA.pl
use DBI
In scriptB.pl, there is require \"scriptA.pl\"
scriptB.pl
require \"scriptA.pl\"
But we still cannot use DB
There are ways, but they are all more ugly, hacky and unclean than simply typing use DBI; in every file that uses it. This is the best practice and is quite normal.
use DBI;