# Foo.pm
package Foo;
use base 'Exporter';
our @EXPORT = qw/ foo_init foo_begin /;

{
    my $thing;
    INIT { $thing = 'init' };
    sub foo_init {
        print "init: $thing";
    }
}
{
    my $thing;
    BEGIN { $thing = 'begin' };
    sub foo_begin {
        print "begin: $thing";
    }
}

1;

# Bar.pm
package Bar;
use Foo;

# This can be put in &import if you
# think that's more real-world.
foo_init();
foo_begin();

1;

# foo.pl
#!/usr/bin/perl -wl
use Bar;