# Optionally in seperate file Opts.pm
package Opts;  
use Getopt::Std;
our %opts;
our @EXPORT = qw( %opts );
our @ISA = 'Exporter';
require Exporter;
getopts('fs', \%opts);
1;

package Foo;
use Opts qw( %opts );
if ($opts{s}) { #do stuff }

package Bar;
use Opts qw( %opts );  # Safe to do multiple times.
if ($opts{s}) { #do stuff }