use strict; 
use warnings;

my @units = qw(foo.pm bar.pm);
    # Alle Funtionen heißen sub foo

my $arg = 0;
foreach my $unit(@units){
    my $packname = $unit;
    $packname =~ s/\W//g;
    my $source = do{
        my $fh = IO::File->new;
        $fh->open($unit, "r") or die $!;
        read($fh, my $buffer, -s $fh);
        $fh->close;
        "package $packname;\n".$buffer;
    };
    eval "$source" or die $@;
    my $coderef = $packname->can('foo');

    $coderef->(++$arg);
}