#!/usr/bin/perl
  use DB_File;

  my $file = shift || die "usage: $0 file";

  %hash = ();
  tie %hash, 'DB_File', $file, O_RDONLY, 0666, DB_HASH
    or die "can't read file '$file': $!";

  print "$file has ", scalar(keys %hash), " entries\n";
  print map { "  $_ => $hash{$_}\n" } sort keys %hash;