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John Karr > String-Validator-Password-0.94 > String::Validator::Password



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Module Version: 0.94   Source   Latest Release: String-Validator-Password-2.00


String::Validator::Password - Check a string against a number of common password rules.


Version 0.94


String::Validator::Password is part of the String Validator Collection. It will check a string against any number of password validation rules, and optionally against a second string (as in password confirmation box on a webform). The primary Negative method returns 0 if the password passes all tests, or a string describing the errors if it fails. The Positive Method returns 1 if the string passes and 0 if it fails. The ErrString method returns the errors from the last string processed.

String::Validator Methods and Usage ^

Provides and conforms to all of the standard String::Validator methods, please see String::Validator for general documentation.

Methods Specific to String::Validator::Password ^

Parameters to New

Require or Deny Classes of Character

SVP knows about four classes of character -- uc (Upper Case), lc (Lower Case), num (Digits), and punct (Everything Else). Types can be required or denied. Thus these 8 arguments require_lc, require_uc, require_nums, require_punct, deny_punct, deny_lc, deny_uc, deny_nums, all of which take a numeric argument, and all of which default to 0 if omitted.

When requiring and denying classes of characters the values of 0 and 1 work as expected, where 0 means not to check this condition at all and 1 means to accept or reject based on the presence of just 1 instance of the type. However, when used to set an amount, require is interpreted as require at least X of this type, while deny is deny if X or more are encountered. require_lc => 2 will result in a string with 2 or more lowercase characters passing the test. deny_lc => 2 will result in a string with 2 lowercase characters being rejected, but would pass a string with 1 lowercase character.

Minimum number of Classes of Character

min_types is used to specify the number of different character types required, default is 2.

Minimum and Maximum Length

min_len and max_len determine the respective minimum and maximum length password to accept. Defaults are 6 and 64.

Examples ^

To create a new instance, with all of the default values:

 my $Validator = String::Validator::Password->new() ;

Specify all of the default values:

 my $Validator = String::Validator::Password->new(
        require_lc => 0,
        require_uc => 0,
        require_punct => 0,
        require_num => 0,
        deny_lc => 0,
        deny_uc => 0,
        deny_punct => 0,
        deny_num => 0,
        min_types => 2,
        min_len => 6,
        max_len => 64,
        ) ;
 ) ;

Normally you would only specify values that were not the default.

 my $Validator = String::Validator::Password->new(
        require_lc => 2,
        require_uc => 2,
        min_types => 3,
        min_len => 8,
        max_len => 18,
        ) ;

Then to check a password you might write something like this:

 if( $Validator->IsNot_Valid( $password1, $passwordconfirm ) ) {
  die $Validator->errstr() ; }


Provide support for custom regexes, custom allow/deny lists, and checking against weak password dictionaries.


John Karr, <brainbuz at>


Please report any bugs or feature requests to bug-string-validator-password at, or through the web interface at I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.


You can find documentation for this module with the perldoc command.

    perldoc Validator

You can also look for information at:



Copyright 2012 John Karr.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 3 or at your option any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

A copy of the GNU General Public License is available in the source tree; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

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