# function

sub do_thing {
    my ($name, $country) = @_;   
    print "Person's name: $name, country: $country\n";
}

# file

{
    # file handle is scoped to this block

    open my $fh, '<', 'file.txt' or die $!;
    
    while (my $line = <$fh>){

        # we're now in a lower-level scope

        print "$line\n";
    }
}

# file handle is closed and unavailable here