#!/usr/bin/perl
use strict;
use warnings;
use Getopt::Std;
use Data::Dumper;

my %opts;
getopts('hif:', \%opts) || usage();
usage() if($opts{h}); # <== ohne exists

print Dumper(\%opts);

sub usage
{
  print "USAGE: $0 -h -i -f <file>\n";
  exit;
}