#!/usr/bin/perl
use strict;
sub screwed {
  my ($in) = @_;
  open(IN, "<$in");
  while(<IN>) { print "file $in contains $_"; }
  close(IN);
}
my @instances = ("a", "b");
map { print "before $_\n" } @instances;
map { screwed "$_"; } @instances;
map { print "after $_\n" } @instances;