1:foreach (sort(<*>)) {
2:        $a = $_;
3:        s/ /_/g;
4:        s/(%20)/_/ig;
5:        s/(%25)//ig;
6:        $_ = lc($_);
7:        rename("$a", $_);
8:}


##</code><code>##

foreach my $old( <*> ) {
	(my $new = lc $old) =~ s/ |%20/_/g;
	$new =~ s/%25//g;
	rename( $old, $new ) or warn "can't rename $old to $new: $!\n";
}