the code "works" mostly, it's populating the arrays.

you are just printing empty lines instead of the content of the arrays.

update

Plz be aware that you are excluding any file or dir starting with a dot.

use strict;
use warnings;

use Data::Dump qw/pp/;

my $path="/tmp";
opendir ( DIR, $path ) || die "Error in opening dir $path\n";

my (@file,@dir);

while (my $filename=readdir(DIR)) {
  next if ($filename =~ m/^\./);
  if (-f $filename) {
    push(@file,$filename);
    # print "\n";
  } elsif (-d $filename){
    push(@dir,$filename);
    # print "\n";
  }
}

pp \@file,\@dir;
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