--- tree.pl     2015-10-13 11:59:07.665138800 +0200
+++ tree_afr.pl 2015-10-13 11:58:27.145867300 +0200
@@ -5,11 +5,13 @@
 use Pod::Usage;

 my (
+    $showall,   # show all, including entries starting with .
     $showfiles, # show also files
     $showlinks, # show also a symlink's target
 );

 help() unless GetOptions(
+    a        => \$showall,
     l        => \$showlinks,
     f        => \$showfiles,
     'h|help' => \&help,
@@ -33,6 +35,7 @@
     opendir my $dh, $path or die "Couldn't read $path: $!\n";
     # Get all directory content - leaving out files unless asked for
     my(@content) = grep { !/^\.\.?$/ and ( $showfiles or not -f "$path/$_" ) } readdir $dh;
+    @content = grep { !/^\./ } @content unless $showall;
     closedir $dh;

     # How many eitems are in the directory?