#!/usr/bin/perl

use strict;
use warnings;

my $a = my $b = my $c = join '', map(chr, 32 .. 126);
print "a = $a\n";

$a =~ s/\W//g;
$a =~ s/_//g;
$b =~ s/\W|_//g;

# allow letters, numbers, and dots
$c =~ s/[^a-z0-9.]//gi;

print "a = $a\n";
print "b = $b\n";
print "c = $c\n";

__END__
[download]