# This is file P.pm
package P;
use strict;
use warnings;
use PX;
....
eval {
  PX::myfunc(...);
};
if($@) {
  print "Exception!\n";
}
....

# This is file PX.pm
package PX;
use strict;
use warnings;
sub myfunc {
  ...
  print("let's do it\n");
  foreach my $c (@{ $foo->{bar}->{baz} }) {
    oink_oink_oink();
  }
  print "I've done it\n";
}

##</code><code>##

let's do it
Exception!

##</code><code>##

let's do it
Pseudo hashes are deprecated at....

##</code><code>##

use warnings FATAL => qw(all);