sub perlish {
	chomp;

	$_ = realpath($_); # follows links, makes full path

	( -d )
	? ( $processed{$_}
		? ()
		: do {
			my $basedir = $_;
			$processed{$_} = 1; # prevent infinite recursion into links

			# turn results of ls into relative paths before recursion
			# and avoids using chdir
			map &perlish, ( map {"$basedir/$_"} `ls $_` );
		}
	  )
	: $_;
}

%processed = ( getcwd() => 1 );
print join "\n", (map &perlish, `ls`),"\n";