my $urls = '(http|telnet|gopher|file|wais|ftp|mailto)';
my $ltrs = '\w';
my $gunk = '/#~:.?+=&%@!\-';
my $punc = '.:?\-';
my $junk   = qq~="'>~; # added

my $any = "${ltrs}${gunk}${punc}";

$text =~ s{([^$junk]\s*\b)($urls:[$any] +?)(?=[$punc]* [^$any]|$) }{$1<a href="$2">$2</a>}igox;
$text =~ s{^($urls:[$any] +?)(?=[$punc]* [^$any]|$) }{<a href="$1">$1</a>}igox;