Add Hide hidden flag

From feature request to respect the .gitignore file. Decided to bundle in
respect for hidden files into the same feature [otherwise if you obey
the .gitignore file you still endup showing the .git directory]

src/main.rs

@@ -126,6 +126,12 @@ fn main() {
                 .long("filecount")
                 .help("Directory 'size' is number of child files/dirs not disk size"),
         )
+        .arg(
+            Arg::with_name("ignore_hidden")
+                .short("i") // Do not use 'h' this is used by 'help'
+                .long("ignore_hidden")
+                .help("Obey .git_ignore rules & Do not display hidden files"),
+        )
 
         .arg(Arg::with_name("inputs").multiple(true))
         .get_matches();
@@ -165,6 +171,7 @@ fn main() {
         None => None,
     };
     let by_filecount = options.is_present("by_filecount");
+    let show_hidden = !options.is_present("ignore_hidden");
 
     let simplified_dirs = simplify_dir_names(target_dirs);
     let (permissions, nodes) = get_dir_tree(
@@ -173,6 +180,7 @@ fn main() {
         use_apparent_size,
         limit_filesystem,
         by_filecount,
+        show_hidden,
         depth,
     );
     let sorted_data = sort(nodes);

src/utils/mod.rs

@@ -81,16 +81,19 @@ pub fn simplify_dir_names<P: AsRef<Path>>(filenames: Vec<P>) -> HashSet<PathBuf>
 fn prepare_walk_dir_builder<P: AsRef<Path>>(
     top_level_names: &HashSet<P>,
     limit_filesystem: bool,
+    show_hidden: bool,
     max_depth: Option<usize>,
 ) -> WalkBuilder {
     let mut it = top_level_names.iter();
     let mut builder = WalkBuilder::new(it.next().unwrap());
     builder.follow_links(false);
+    if show_hidden {
+        builder.hidden(false);
         builder.ignore(false);
         builder.git_global(false);
         builder.git_ignore(false);
         builder.git_exclude(false);
-    builder.hidden(false);
+    }
 
     if limit_filesystem {
         builder.same_file_system(true);
@@ -110,6 +113,7 @@ pub fn get_dir_tree<P: AsRef<Path>>(
     apparent_size: bool,
     limit_filesystem: bool,
     by_filecount: bool,
+    show_hidden: bool,
     max_depth: Option<usize>,
 ) -> (bool, HashMap<PathBuf, u64>) {
     let (tx, rx) = channel::bounded::<PathData>(1000);
@@ -119,7 +123,8 @@ pub fn get_dir_tree<P: AsRef<Path>>(
     let t2 = HashSet::from_iter(top_level_names.iter().map(|p| p.as_ref().to_path_buf()));
 
     let t = create_reader_thread(rx, t2, apparent_size);
-    let walk_dir_builder = prepare_walk_dir_builder(top_level_names, limit_filesystem, max_depth);
+    let walk_dir_builder =
+        prepare_walk_dir_builder(top_level_names, limit_filesystem, show_hidden, max_depth);
 
     walk_dir_builder.build_parallel().run(|| {
         let txc = tx.clone();