Here's a way that avoids re-creating the local sub every invocation of the main, and avoids namespace pollution in main. It also allows as many (named) "local" subs as required.

#! perl -slw
use strict;

sub test{
    ## create a 'local' sub the first time we're called
    ## As many as you like each with it's own name
    *test->{localsub} = sub{
        print 'localsub1';
        return 12345;
    } unless exists *test->{localsub};
    
    ## use it
    *test->{localsub}();
}

print test;

## It's not truly local, but no namespace pollution.
## Anyone doing this, is doing it deliberately
*test->{localsub}();

__END__
P:\test>test
localsub1
12345
localsub1
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