First of all, while reading through the script in more detail, i noticed that not everything works as expected. For example, the "special characters" option was missing, no help/usage information on command line, version info on command line was missing too. So i've gone ahead and fixed that.

Frankly, i didn't really see the added value/security of using irand() from Math::Random::Secure in this specific use case. So i decided to change to rand() instead, which also reduces external dependencies and therefore generated file size.

Here's the updated source code:

#!/usr/bin/perl
#
# pwgen 1.0
#
#   Usage: pwgen [-h] [-s] [length]
#
#          length - an optional argument indicating the length of the 
+password
#          -s     - use special characters
#          -h     - display usage
#
# This will generate random passwords of the specified or default leng
+th.
# Requires the Perl package Math::Random::Secure to produce
# cyptographically secure passwords.
#
# Copyright (C) 2012 - Paul E. Jones <paulej@packetizer.com>
# Permission to use, copy, modify and distribute this software is gran
+ted.
#
# Fixed, expanded and compiled by Rene "cavac" Schickbauer for PerlMon
+ks, see
# http://www.perlmonks.org/index.pl?node_id=946871

use strict;
use warnings;
use 5.010;

# Define the default password length
use constant DEFAULT_PASSWORD_LENGTH => 12;

#
# MAIN
#

# init to defaults
my $password_length = DEFAULT_PASSWORD_LENGTH;
my $use_special = 0;

# simple-minded grabbing of values from @ARGV
foreach my $arg (@ARGV) {
    given($arg) {
        when('-s') {
            $use_special = 1;
            next;
        }
        when('-h') {
            showUsage();
            exit(0);
        }
        when('-v') {
            showVersion();
            exit(0);
        }
    }
    
    $arg = (0 + $arg); # convert to numeric
    if($arg > 0) {
        $password_length = $arg;
    }
}

print GeneratePassword($password_length,$use_special) . "\n";

exit(0); # Finish without error


#
# GeneratePassword
#
#     Description
#         This routine will generate a password and return it as a str
+ing.
#         By default, it will not utilize special characters like "~" 
+in
#         passwords, but if the second argument is a 1, it will.  Note
+ that
#         use of special characters provides only minimum additional s
+trenth,
#         yet they are not very friendly for humans. For details, visi
+t
#         https://secure.packetizer.com/pwgen/.
#
#     Parameters
#         length [in]
#             The length of the password
#         special [in]
#             Indicates whether to use special characters other than
#             the letters A-Z, a-z, and digits 0-9.
#
#     Returns
#         A string containing the password, or an empty string if ther
+e
#         was an error producing the password.
#
sub GeneratePassword
{
    my ($length, $special) = @_;
    my $password = "";

    my @pwchars = (
        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c
+', 'd',
        'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q
+', 'r',
        's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E
+', 'F',
        'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S
+', 'T',
        'U', 'V', 'W', 'X', 'Y', 'Z', '~', '`', '!', '@', '#', '$', '%
+', '^',
        '&', '*', '(', ')', '_', '+', '=', '-', '{', '}', '|', '\\', '
+]', '[',
        ':', '"', '\'', ';', '<', '>', '?', '/', '.'
    );

    for(1 .. $length) {
        if ($special) {
            $password .= $pwchars[int(rand(93))];
        } else {
            $password .= $pwchars[int(rand(62))];
        }
    }

    return $password;
}

sub showUsage {
    print <<ENDUSAGE;
   Usage: pwgen [-h] [-s] [length]

          length - an optional argument indicating the length of the p
+assword
          -s     - use special characters
          -h     - display usage
          -v     - display version
ENDUSAGE
}

sub showVersion {
    print <<ENDVERSION;
 pwgen 1.0

 This will generate random passwords of the specified or default lengt
+h.
 Requires the Perl package Math::Random::Secure to produce
 cyptographically secure passwords.

 Copyright (C) 2012 - Paul E. Jones <paulej\@packetizer.com>
 Permission to use, copy, modify and distribute this software is grant
+ed.

 Fixed, expanded and compiled by Rene "cavac" Schickbauer for PerlMonk
+s, see
 http://www.perlmonks.org/index.pl?node_id=946871    
ENDVERSION
}
[download]

Ok, here is the link to the executable. Please tell me as soon as you downloaded it, i'll be deleting it from my server then.