my $configFile = "config.dat";

my $config;

unless (open (FH, $configFile)) {
  die "Error: can't open '$configFile': $!\n";
}
else {
  local $/; 
  my $code = <FH>;
  close (FH);

  $code =~ s/^return\s*=>/\$config = /;
  eval "$code";
  die $@ if $@;
}