package Parent;
sub foo { print "foo in parent(@_)\n"; };
sub bar { print "bar in parent(@_)\n"; };
package Child;
@ISA = qw(Parent);
sub foo { print "foo in child(@_)\n"; };
package main;

eval { Child::foo(); }; warn $@ if $@;
eval { Child->foo(); }; warn $@ if $@;
eval { Child::bar(); }; warn $@ if $@;
eval { Child->bar(); }; warn $@ if $@;