diff --git a/src/cli.rs b/src/cli.rs
index 0bdc64f..49ecd98 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -38,14 +38,14 @@ pub struct CliOpts {
     #[arg(short, long, help = "specify the number of times to execute sibling", value_name = "COUNT", default_value_t = 1)]
     pub step: i32,
 
-    #[arg(short, long, help = "generate the initialize script for the shell", value_name = "SHELL", hide = true)]
+    #[arg(short, long, help = "generate the initialize script for the shell", value_name = "SHELL", hide = true, default_missing_value = "bash")]
     pub init: Option<String>,
 
     #[arg(short = 't', long = "type", help = "specify the nexter type", value_enum, default_value_t = NexterType::Next, value_name = "TYPE", ignore_case = true)]
     pub nexter: NexterType,
 
-    #[arg(index = 1, help = "the directory for listing the siblings", value_name = "DIR", default_value = ".")]
-    pub dir: PathBuf,
+    #[arg(index = 1, help = "the target directory", value_name = "DIR")]
+    pub dirs: Vec<PathBuf>,
 }
 
 #[derive(Debug, Parser)]
diff --git a/src/dirs.rs b/src/dirs.rs
index 68b1929..4d8f773 100644
--- a/src/dirs.rs
+++ b/src/dirs.rs
@@ -15,7 +15,7 @@ impl Dirs {
         if current_dir == PathBuf::from(".") {
             match std::env::current_dir() {
                 Ok(dir) => 
-                    build_dirs(current_dir.parent(), dir),
+                    build_dirs(dir.clone().parent(), dir),
                 Err(e) => Err(SiblingError::Io(e)),
             }
         } else if current_dir.exists() {
@@ -92,10 +92,18 @@ mod tests {
 
     #[test]
     fn test_dirs_new() {
-        let dirs = Dirs::new(PathBuf::from("testdata/b"));
+        let dirs = Dirs::new(PathBuf::from("testdata/d"));
         assert!(dirs.is_ok());
         let dirs = dirs.unwrap();
         assert_eq!(dirs.dirs.len(), 26);
-        assert_eq!(dirs.current, 1);
+        assert_eq!(dirs.current, 3);
+    }
+
+    #[test]
+    fn test_dir_dot() {
+        let dirs = Dirs::new(PathBuf::from("."));
+        assert!(dirs.is_ok());
+        let dirs = dirs.unwrap();
+        assert_eq!(dirs.current_path().file_name().map(|s| s.to_str()), Some("sibling".into()));
     }
 }
diff --git a/src/main.rs b/src/main.rs
index edecced..01b1e45 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,5 @@
+use std::path::PathBuf;
+
 use clap::Parser;
 use crate::cli::{CliOpts, PrintingOpts, Result, SiblingError};
 use crate::nexter::Nexter;
@@ -8,20 +10,43 @@ mod init;
 mod nexter;
 mod printer;
 
-fn perform_impl(mut dirs: dirs::Dirs, nexter: Box<dyn Nexter>, step: i32, opts: PrintingOpts) -> Result<String> {
+fn perform_impl(mut dirs: dirs::Dirs, nexter: &Box<dyn Nexter>, step: i32, opts: &PrintingOpts) -> Result<String> {
     nexter.next(&mut dirs, step);
     printer::result_string(&dirs, opts)
 }
 
-fn perform(opts: CliOpts) -> Result<String> {
+fn perform_each(dir: std::path::PathBuf, nexter: &Box<dyn Nexter>, step: i32, opts: &PrintingOpts) -> Result<String> {
+    match dirs::Dirs::new(dir) {
+        Err(e) => Err(e),
+        Ok(dirs) => perform_impl(dirs, nexter, step, opts),
+    }
+}
+
+fn perform_sibling(opts: CliOpts) -> Vec<Result<String>> {
+    let nexter = nexter::build_nexter(opts.nexter);
+    let target_dirs = if opts.dirs.is_empty() {
+        vec![std::env::current_dir().unwrap()]
+    } else {
+        opts.dirs
+    };
+    let mut result = vec![];
+    for dir in target_dirs {
+        let dir = if dir == PathBuf::from(".") {
+            std::env::current_dir().unwrap()
+        } else {
+            std::path::PathBuf::from(dir)
+        };
+        let r = perform_each(dir, &nexter, opts.step, &opts.p_opts);
+        result.push(r);
+    }
+    result
+}
+
+fn perform(opts: CliOpts) -> Vec<Result<String>> {
     if let Some(shell) = opts.init {
-        init::generate_init_script(shell)
+        vec![init::generate_init_script(shell)]
     } else {
-        let nexter = nexter::build_nexter(opts.nexter);
-        match dirs::Dirs::new(opts.dir) {
-            Err(e) => Err(e),
-            Ok(dirs) => perform_impl(dirs, nexter, opts.step, opts.p_opts),
-        }
+        perform_sibling(opts)
     }
 }
 
@@ -39,9 +64,38 @@ fn print_error(e: &SiblingError) {
 }
 
 fn main() {
-    let opts = cli::CliOpts::parse();
-    match perform(opts) {
-        Ok(result) => println!("{}", result),
-        Err(e) => print_error(&e),
+    let mut args = std::env::args();
+    let args = if args.len() == 1 {
+        vec![args.next().unwrap(), ".".into()]
+    } else {
+        args.collect()
+    };
+    let opts = cli::CliOpts::parse_from(args);
+    for item in perform(opts) {
+        match item {
+            Ok(result) => println!("{}", result),
+            Err(e) => print_error(&e),
+        }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_nexter_example() {
+        let opts_r = cli::CliOpts::try_parse_from(vec!["sibling", "."]);
+
+        if let Err(e) = &opts_r {
+            eprintln!("{}", e);
+        }
+        assert!(opts_r.is_ok());
+        let r = perform(opts_r.unwrap());
+        assert_eq!(r.len(), 1);
+        match r.get(0).unwrap() {
+            Err(e) => print_error(&e),
+            Ok(result) => println!("{}", result),
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/nexter.rs b/src/nexter.rs
index 090fee1..ebd0868 100644
--- a/src/nexter.rs
+++ b/src/nexter.rs
@@ -83,7 +83,6 @@ fn next_impl(dirs: &mut Dirs, step: i32) -> Option<PathBuf> {
     } else {
         dirs.dirs.get(dirs.next as usize)
     };
-    dirs.current = dirs.next as usize;
     r.map(|f| f.to_path_buf())
 }
 
@@ -122,7 +121,7 @@ mod tests {
             Some(p) => assert_eq!(p, PathBuf::from("testdata/d")),
             None => panic!("unexpected None"),
         }
-        match nexter.next(&mut dirs, 1) {
+        match nexter.next(&mut dirs, 2) {
             Some(p) => assert_eq!(p, PathBuf::from("testdata/e")),
             None => panic!("unexpected None"),
         }
@@ -144,8 +143,12 @@ mod tests {
             Some(p) => assert_eq!(p, PathBuf::from("testdata/j")),
             None => panic!("unexpected None"),
         }
+        match nexter.next(&mut dirs, 1) {
+            Some(p) => assert_eq!(p, PathBuf::from("testdata/j")),
+            None => panic!("unexpected None"),
+        }
         match nexter.next(&mut dirs, 4) {
-            Some(p) => assert_eq!(p, PathBuf::from("testdata/f")),
+            Some(p) => assert_eq!(p, PathBuf::from("testdata/g")),
             None => panic!("unexpected None"),
         }
         match nexter.next(&mut dirs, 26) {
diff --git a/src/printer.rs b/src/printer.rs
index 33bc7d4..da3c5ad 100644
--- a/src/printer.rs
+++ b/src/printer.rs
@@ -3,7 +3,7 @@ use std::path::PathBuf;
 use crate::cli::{PrintingOpts, Result};
 use crate::dirs::Dirs;
 
-pub(crate) fn result_string(dirs: &Dirs, opts: PrintingOpts) -> Result<String> {
+pub(crate) fn result_string(dirs: &Dirs, opts: &PrintingOpts) -> Result<String> {
     if opts.csv {
         csv_string(dirs, opts.absolute)
     } else if dirs.no_more_dir {
@@ -22,7 +22,7 @@ fn csv_string(dirs: &Dirs, absolute: bool) -> Result<String> {
             dirs.current + 1, dirs.next + 1, dirs.dirs.len()))
 }
 
-fn no_more_dir_string(dirs: &Dirs, opts: PrintingOpts) -> Result<String> {
+fn no_more_dir_string(dirs: &Dirs, opts: &PrintingOpts) -> Result<String> {
     if opts.parent {
         Ok(pathbuf_to_string(Some(dirs.parent.clone()), opts.absolute))
     } else {
@@ -30,7 +30,7 @@ fn no_more_dir_string(dirs: &Dirs, opts: PrintingOpts) -> Result<String> {
     }
 }
 
-fn list_string(dirs: &Dirs, opts: PrintingOpts) -> Result<String> {
+fn list_string(dirs: &Dirs, opts: &PrintingOpts) -> Result<String> {
     let mut result = vec![];
     for (i, dir) in dirs.dirs.iter().enumerate() {
         let prefix = if i == dirs.next as usize { "> " }
@@ -39,12 +39,12 @@ fn list_string(dirs: &Dirs, opts: PrintingOpts) -> Result<String> {
         } else {
             "  "
         };
-        result.push(format!("{}{}: {}", i + 1, prefix, pathbuf_to_string(Some(dir.to_path_buf()), opts.absolute)));
+        result.push(format!("{:>4} {}{}", i + 1, prefix, pathbuf_to_string(Some(dir.to_path_buf()), opts.absolute)));
     }
     Ok(result.join("\n"))
 }
 
-fn result_string_impl(dirs: &Dirs, opts: PrintingOpts) -> Result<String> {
+fn result_string_impl(dirs: &Dirs, opts: &PrintingOpts) -> Result<String> {
     let r = if opts.progress {
         format!("{} ({}/{})", pathbuf_to_string(dirs.next_path(), opts.absolute), dirs.next + 1, dirs.dirs.len())
     } else {