PERL password generation script (genpass)

[munkyeetr]

This is a password generation script I have written. Any feedback, critiques, or suggestions would be much appreciate.

#!/usr/bin/perl

## ***************************************************************************
#
#  genpass v1.0 (06.2007) Password Generation Program
#  Copyright (C) 2007 Jon Brown
#
#  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; either version 2 of the License, or
#  (at your option) any later version.
#
#  To read the full text go to http://www.gnu.org/licenses/gpl.txt
#
#  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.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
## ***************************************************************************

use strict;
use warnings;
use Getopt::Long;
Getopt::Long::Configure ("bundling");

## PARSE AND SET COMMAND-LINE OPTIONS
## -----------------------------------------------------
my %flags=('symbols', 0, 'numbers', 0, 'uppercase', 0, 'lowercase', 0, 'confusable', 0, 'help', 0, 'qty', 1, 'version', 0);

GetOptions( 's|S|symbols' => \$flags{symbols},
	    'n|N|numbers' => \$flags{numbers},
	    'u|U|uppercase' => \$flags{uppercase},
	    'l|L|lowercase' => \$flags{lowercase},
	    'c|C|confusable' => \$flags{confusable},
	    'q|Q:i' => \$flags{qty},
	    'help' => \$flags{help},
	    'ver|version' => \$flags{version} );

# Set password characters, excluding those flagged on the command-line
my $pwdchars = join( '', map {chr} ( 0x21 .. 0x7e ));
	$pwdchars =~ s/\d+//	if ( $flags{numbers} );
	$pwdchars =~ s/[A-Z]+// if ( $flags{uppercase} );
	$pwdchars =~ s/[a-z]+// if ( $flags{lowercase} );
	$pwdchars =~ s/[_\W]+//g if ( $flags{symbols} );
	$pwdchars =~ tr/1Il0O//d  if ( $flags{confusable} );

# If user triggered the --help option flag, display and exit
if ($flags{help}) {			
	&DisplayUsage();	
	exit();
}
elsif ($flags{version}) {
	&DisplayVersion();
	exit();
}

## START VALIDATE INPUT
## -----------------------------------------------------
my $kill=0;		# flag to stop the script if input is invalid (or --help is used)
my @errmsg;		# error message descriptions

# If -q option was used to set a quantity of passwords, make sure it contains at
# least a value of 1 so that a password can be generated
if ($flags{qty} == 0 || $flags{qty} < 0) {
	$flags{qty}=1;
}

# Check that user hasn't excluded all character-types, warn user, kill script
if ( length($pwdchars) == 0) {
	push @errmsg, "** 0x1: At least 1 character-type must be included";	
	$kill=1;
}

# Check that user has passed only 1 argument (LENGTH) other than options flags, warn user, kill script
if ($#ARGV > 0 || $#ARGV < 0) {
	push @errmsg, "** 0x2: Incorrect number of arguments passed";
	$kill=1;
}

# Check for only numeric input in LENGTH argument, warn user, kill script
if ($ARGV[0] !~ /^[0-9]+$/) {
		push @errmsg, "** 0x3: Invalid input. LENGTH argument must be a numeric value";
		$kill=1;
}

# If any of the above validation tests triggered the $kill flag...
if ($kill == 1) {				 	
	print "\n** GENPASS ERROR ---------------------------------------------------------";
	print "\n** ".@errmsg." Error(s) found";  	# display number of errors	
	foreach my $err (@errmsg) {		 	# display error messages
		print "\n".$err;
	}
	print "\n**\n** Type genpass --help for command usage\n";
	print "** -----------------------------------------------------------------------\n\n";
	exit();					 	# exit script
}
## END VALIDATE INPUT

## START MAIN SCRIPT
## -----------------------------------------------------
# From 1 to qty

for ( 1..$flags{qty} ) {
	print &GenPass( $ARGV[0] )."\n";
}
exit();

## END MAIN SCRIPT

## FUNCTION DEFINITIONS
## -----------------------------------------------------
sub GenPass() {
	my ($pwdlen) = @_;
	my $limit = length( $pwdchars );
	my $pwd = '';
    
	for ( 0..$pwdlen-1 ) {
        	$pwd .= substr( $pwdchars, rand( $limit ), 1 );
	}

	return $pwd;
}

# use Here-Documents to display usage text
sub DisplayUsage {
    print <<"USAGE";

  Usage: genpass [-snulcqX] LENGTH
  Generate secure passwords LENGTH characters long.
    
    -s, --symbols\tExclude symbols.
    -n, --numbers\tExclude numbers.
    -u, --uppercase\tExclude uppercase letters.
    -l, --lowercase\tExclude lowercase letters.

    -c, --confusable\tExclude confusable characters like: l,I,1,0,O
        
    -qX\t\t\tCreate X number of passwords.
        
    --help\t\tDisplay Usage information.
    --ver, --version\tDisplay version and license information.
        
  Report bugs, comments, and questions to jbrown_home\@yahoo.ca
    
USAGE
}

# use Here-Documents to display version text
sub DisplayVersion {
print <<"VER";
  genpass v1.0 (06.2007) Copyright 2007 Jon Brown

  This is free software.  You may redistribute copies of it under the terms of
  the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.
  There is NO WARRANTY, to the extent permitted by law.

  Written by Jon Scott Brown
VER
}
__END__

[RobinVossen]

Use crypt aswell ^^

Heh sorry I am new to Perl and thats the only Encrypting I know for Perl

Well, your code looks 1337