Example: 
use Validate::Hash;
my $vh = new Validate::Hash(
            required => ['Fred', 'Wilma'],
            optional => ['Barney', 'Betty'],
            verify   => {Barney => qr/\d+/, 
                         Fred => qr/\w+/},
            -errs    => {illegal =>  "#KEY# is illegal",
                         required => "#KEY# is required!",
                         notmatch => 
                     "the value #KEY#, #VALUE#, doesn't match /#PATTER
+N#/",
            -strict => 1,
);

my %hash = (Fred => 'A', Barney => 1);

$vh->valid(\%hash); # returns false, 
$vh->get_error();   # returns 'Wilma is required!'

[download]
From the README: 

 /*************** README ***************\
|            ValidateHash v1.4           |
 \**************************************/

***** Summary
This module provides Object-Oriented way to validate the contents of a hash.
It should be useful for CGI-ish forms or for validating the arguments of functions.
Whatever floats your boat.


To install, just:
% perl Makefile.PL
% make
% make install

Validate::Hash is documented by its own POD. I suggest you read it by typing:
% perldoc Validate::Hash


***** Copyright:
This perl module is Copyright (c) 2002 Dylan William Hardison. All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

***** BUGS:
None known. If you find a bug, please email me with the details, or better yet, a patch,
and I'll see to it that it is fixed ASAP.

In reply to Validate::Hash by Dylan

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