### file Myconnection.pl
use DBI;
{
    my $dsn = 'whatever';
    my $user = 'joe';
    my $pass = 'joe';
    my $opts = {
                   RaiseError => 1,
                   AutoCommit => 0,
               };
    sub myconnect () {
        DBI->connect($dbs, $user, $pass, $opts);
    }
}

##</code><code>##

use lib '/home/user/lib/perl5'; # or wherever
use 'Myconnection.pl';

my $dbh = myconnect();