using standard module:
<code perl>
use File::Find;

find({ wanted => sub {
	# for each file
	# $_                 is file name
	# $File::Find::name  is full path
	# $File::Find::dir   is directory path
}, preprocess => sub {
	# process the list of files about to be wanted()
	# $File::Find::dir   is directory path
	return @_;
}, follow => 0, # follow symlinks?
no_chdir => 0, # dont chdir (so $_ equals $File::Find::name)
}, @directories);

</code>

manually:

<code perl>
use strict;

sub act {
	my ($file) = @_;
	
	print "$file\n";
}

sub traverse {
	my ($path,$wildcard) = @_;
	
	$path =~ s#/+$##;

	# Could be more efficient with an opendir
	for my $file (glob("$path/*")) {
		next unless (-d $file);
		# actions to dirs go here
		traverse($file,$wildcard);
	}
	for my $file (glob("$path/$wildcard")) {
		act($file) if (-f $file);
	}
}

my $path = $ARGV[0] || '.';
my $wildcard = $ARGV[1] || '*';

&traverse($path,$wildcard);

</code>