When calling getopts(), its often useful to die with a usage string on failure. Something like:

(my $cmd = $0) =~ s#.*/##;
my $usage_str = <<EOT
Usage: $cmd [-hulf] [-f file]
'Explanation of above command and options'
EOT

getops('hulf:', \%opts) or die $usage_str;
[download]

Sorry I don't have time to be more critical at the moment :)