diff --git a/src/bin/rbcat.rs b/src/bin/rbcat.rs
index 078e9ce..53fc18f 100644
--- a/src/bin/rbcat.rs
+++ b/src/bin/rbcat.rs
@@ -1,5 +1,5 @@
 use std::{env, fs};
-use std::io::{self, BufRead};
+use std::io::{self, BufRead, ErrorKind::*};
 
 fn main() -> Result<(), io::Error> {
     if env::args().len() < 2 {
@@ -15,8 +15,8 @@ fn main() -> Result<(), io::Error> {
             Ok(contents) => print!("{}", contents),
             Err(error) => {
                 let msg = match error.kind() {
-                    io::ErrorKind::PermissionDenied => "Permission denied",
-                    io::ErrorKind::NotFound => "No such file or directory",
+                    PermissionDenied => "Permission denied",
+                    NotFound => "No such file or directory",
                     _ => "Unexpected I/O error"
                 };
                 eprintln!("rbcat: {}: {}", file_name, msg);
diff --git a/src/bin/rbls.rs b/src/bin/rbls.rs
index 0bc017a..24c1be9 100644
--- a/src/bin/rbls.rs
+++ b/src/bin/rbls.rs
@@ -1,27 +1,57 @@
 use clap::Parser;
-use console::Term;
-use std::io::{self, Write};
+use std::io::{self, ErrorKind::*};
 use std::fs::{self, DirEntry, Metadata};
 
-fn main() -> Result<(), io::Error> {
+// TODO: implement more options (-l, -i, etc.)
+fn main() {
     let cli = Cli::parse();
-    let file_infos = get_files_metadata(&cli.files[0])?;
-    let file_names = format_file_names(file_infos, cli.all, cli.almost_all);
-    let term = Term::stdout();
-    let output = if term.is_term() { format_term(file_names, term.size().1) }
-    else { file_names.join(" ") };
-    let mut stdout = io::stdout().lock();
-    write!(stdout, "{}", output)?;
-    writeln!(stdout)?;
-    return Ok(());
+    let mut non_dirs = Vec::<FileInfo>::new();
+    let mut dirs = Vec::<DirInfo>::new();
+    for file_name in &cli.files {
+        let file_infos = match get_file_infos(&file_name) {
+            Ok(file_infos) => file_infos,
+            Err(err) => {
+                // NotADirectory is unstable feature, look at error code instead
+                if err.raw_os_error().unwrap() == 20 {
+                    let metadata = fs::metadata(&file_name).unwrap();
+                    non_dirs.push(FileInfo::new(file_name, metadata));
+                    continue;
+                }
+                let msg = match err.kind() {
+                    PermissionDenied => "Permission denied",
+                    NotFound => "No such file or directory",
+                    _ => "Unexpected I/O error"
+                };
+                eprintln!("rbls: {}: {}", file_name, msg);
+                continue;
+            }
+        };
+        dirs.push(DirInfo::new(file_name, file_infos));
+    }
+    if !non_dirs.is_empty() {
+        let non_dirs_filtered = transform_file_infos(non_dirs, &cli);
+        let non_dirs_output = format_output(non_dirs_filtered, &cli);
+        println!("{}", non_dirs_output);
+    }
+    let dirs_output = if dirs.len() > 1 {
+        dirs.into_iter()
+            .map(|dir| {
+                let files_filtered = transform_file_infos(dir.file_infos, &cli);
+                return dir.name + ":\n" + &format_output(files_filtered, &cli);
+            })
+            .collect::<Vec<String>>()
+            .join("\n\n")
+    } else {
+        let dir = dirs.remove(0);
+        let files_filtered = transform_file_infos(dir.file_infos, &cli);
+        format_output(files_filtered, &cli)
+    };
+    println!("{}", dirs_output);
 }
 
-fn get_files_metadata(file_name: &str) -> Result<Vec<FileInfo>, io::Error> {
-    let Ok(contents) = fs::read_dir(file_name)
-    else {
-        let file_info = FileInfo::new(file_name.to_string(), fs::metadata(file_name)?);
-        return Ok(vec![file_info]);
-    };
+fn get_file_infos(file_name: impl AsRef<str>) -> io::Result<Vec<FileInfo>> {
+    let file_name = file_name.as_ref();
+    let contents = fs::read_dir(file_name)?;
     let mut file_infos = vec![
         FileInfo::new(".".to_string(), fs::metadata(".")?),
         FileInfo::new("..".to_string(), fs::metadata("..")?),
@@ -32,15 +62,19 @@ fn get_files_metadata(file_name: &str) -> Result<Vec<FileInfo>, io::Error> {
     return Ok(file_infos);
 }
 
-fn format_file_names(file_infos: Vec<FileInfo>, show_all: bool, show_almost_all: bool) -> Vec<String> {
-    return file_infos.into_iter()
+fn transform_file_infos(file_infos: Vec<FileInfo>, options: &Cli) -> Vec<String> {
+    let mut filtered_file_infos = file_infos.into_iter()
                 .filter(|file_info| {
-                    if show_all { return true; }
-                    if show_almost_all {
+                    if options.all { return true; }
+                    if options.almost_all {
                         return file_info.name != "." && file_info.name != "..";
                     }
                     return !file_info.name.starts_with(".");
                 })
+                .collect::<Vec<FileInfo>>();
+    // sort alphabetically
+    filtered_file_infos.sort_by(|fi1, fi2| fi1.name.to_lowercase().cmp(&fi2.name.to_lowercase()));
+    return filtered_file_infos.into_iter()
                 .map(|file_info| {
                     let mut file_name = file_info.name;
                     if file_info.metadata.is_dir() { file_name.push('/') }
@@ -49,7 +83,13 @@ fn format_file_names(file_infos: Vec<FileInfo>, show_all: bool, show_almost_all:
                 .collect();
 }
 
-fn format_term(mut file_names: Vec<String>, term_width: u16) -> String {
+fn format_output(file_names: Vec<String>, options: &Cli) -> String {
+    let term = console::Term::stdout();
+    if term.is_term() { return format_tabular(file_names, options, term.size().1); }
+    else { return file_names.join(" "); }
+}
+
+fn format_tabular(mut file_names: Vec<String>, options: &Cli, term_width: u16) -> String {
     let max_file_name_len = file_names.iter().map(|n| n.len()).max().unwrap();
     let elem_width = max_file_name_len + 2;
     let row_elems_amount = (term_width as usize / elem_width).max(1);
@@ -60,12 +100,20 @@ fn format_term(mut file_names: Vec<String>, term_width: u16) -> String {
     return file_names.join("").trim_end().to_string();
 }
 
+struct DirInfo {
+    name: String, file_infos: Vec<FileInfo>
+}
+
+impl DirInfo {
+    fn new(name: impl Into<String>, file_infos: Vec<FileInfo>) -> Self { Self { name: name.into(), file_infos } }
+}
+
 struct FileInfo {
     name: String, metadata: Metadata
 }
 
 impl FileInfo {
-    fn new(name: String, metadata: Metadata) -> Self { Self { name, metadata } }
+    fn new(name: impl Into<String>, metadata: Metadata) -> Self { Self { name: name.into(), metadata } }
 }
 
 impl TryFrom<DirEntry> for FileInfo {
@@ -77,7 +125,7 @@ impl TryFrom<DirEntry> for FileInfo {
     }
 }
 
-impl TryFrom<Result<DirEntry, io::Error>> for FileInfo {
+impl TryFrom<io::Result<DirEntry>> for FileInfo {
     type Error = io::Error;
 
     fn try_from(de: Result<DirEntry, io::Error>) -> Result<Self, Self::Error> { Self::try_from(de?) }
@@ -93,5 +141,11 @@ struct Cli {
     all: bool,
 
     #[arg(short = 'A', long, help = "Same as --all, but doesn't list implied . and ..")]
-    almost_all: bool
+    almost_all: bool,
+
+    #[arg(short, long, help = "Use a long listing format")]
+    long: bool,
+
+    #[arg(short, long, help = "Print the index number of each file")]
+    inode: bool
 }