+}
+
+############################################################################
+
+# finds any directories under the arguments, which can be a list of directories.
+sub find_directories {
+ my @dirs_found = ();
+ my $dir;
+ foreach $dir (@_) {
+ local *DIR;
+ opendir DIR, $dir or die "opendir $dir: $!";
+ while ($_ = readdir DIR) {
+ # skip if it's current or parent dir.
+ next if /^\.{1,2}$/;
+ my $path = "$dir/$_";
+ # skip if this entry is not itself a directory.
+ next if ! -d $path;
+ push @dirs_found, $path;
+ }
+ closedir DIR;
+ }
+ return @dirs_found;
+}
+
+############################################################################
+
+# given a list of paths, this returns an array of all the filenames found therein.
+sub find_files {
+ my @files_found = ();
+ my $dir;
+ foreach $dir (@_) {
+ if (-f $dir) {
+ # that's actually just a file, so add it.
+ push @files_found, $dir;
+ next;
+ }
+ local *DIR;
+ opendir DIR, $dir or die "opendir $dir: $!";
+ while ($_ = readdir DIR) {
+ # skip if it's current or parent dir.
+ next if /^\.{1,2}$/;
+ my $path = "$dir/$_";
+ # skip if this entry is not a file.
+ next if ! -f $path;
+ push @files_found, $path;
+ }
+ closedir DIR;
+ }
+ return @files_found;
+}
+
+############################################################################
+
+# finds all directories starting at a particular directory and returns them
+# in an array. does not include the starting directory.
+sub recursive_find_directories {
+ # first find all the directories within the parameters.
+ my @toplevel = find_directories(@_);
+
+ my @to_return;
+ push(@to_return, @toplevel);
+
+ # return the composition of the list we found here plus any directories under those.
+ # we only recurse if there's something to chew on in our directory list.
+ # otherwise, we've hit the bottom of that tree.
+ if (scalar @toplevel > 0) {
+ my @subs_found = recursive_find_directories(@toplevel);
+ push(@to_return, @subs_found);
+ }
+ return @to_return;