You're passing the arguments to find, which has no interest in them. You want them to be passed to wanted. But since the call to wanted is made by File::Find, you can't pass it extra arguments.

There are two solutions.

• Use a global variable.

  my $size_input;
  
  sub wanted {
     ...
     $size_input
     ...
  }
  
  ...
  $size_input = ...;
  ...
  find({wanted => \&wanted}, $fs_input);
  [download]

  But using globals is undesirable.

• Or have find call a function other than wanted, and have it called wanted with the parameter.

  sub wanted {
     my ($size_input) = @_;
     ...
     $size_input
     ...
  }
  
  {
     my $size_input;
     ...
     $size_input = ...;
     ...
     find({wanted => sub { wanted($size_input) }}, $fs_input);
  }
  [download]