$\ = $/;
sub foo;

print "foo ref is: ",\&foo;

my $ref = \&foo;


for (keys %main::) {
    print "1: ",*{$_}{NAME} if *{$_}{CODE} and *{$_}{CODE} eq $ref;
}

*bar = *foo;

sub foo { print "in foo" }

for (keys %main::) {
    print "2: ",*{$_}{NAME} if *{$_}{CODE} and *{$_}{CODE} eq $ref;
}

bar();

__END__
foo ref is: CODE(0x91cf78c)
1: foo
2: bar
2: foo
in foo