diff --git a/Cargo.toml b/Cargo.toml
index b8bf700..b6ee27c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "totebag"
-version = "0.1.0"
+version = "0.1.1"
 description = "A tool for archiving files and directories and extracting several archive formats."
 repository = "https://github.com/tamada/totebag"
 readme = "README.md"
diff --git a/src/archiver.rs b/src/archiver.rs
new file mode 100644
index 0000000..a9061f3
--- /dev/null
+++ b/src/archiver.rs
@@ -0,0 +1,151 @@
+use std::{ffi::OsStr, path::PathBuf};
+
+pub trait Archiver {
+    fn perform(&self, inout: InOut) -> Result<(), String>;
+    fn format(&self) -> Format;
+}
+
+struct ZipArchiver {
+}
+struct TarArchiver {
+}
+struct TarGzArchiver {
+}
+struct TarBz2Archiver {
+}
+struct RarArchiver {
+}
+
+impl Archiver for  ZipArchiver {
+    fn perform(&self, inout: InOut) -> Result<(), String> {
+        Err("not implement yet".to_string())
+    }
+    fn format(&self) -> Format {
+        Format::Zip
+    }
+}
+impl Archiver for  TarArchiver {
+    fn perform(&self, inout: InOut) -> Result<(), String> {
+        Err("not implement yet".to_string())
+    }
+    fn format(&self) -> Format {
+        Format::Tar
+    }
+}
+impl Archiver for TarGzArchiver{
+    fn perform(&self, inout: InOut) -> Result<(), String> {
+        Err("not implement yet".to_string())
+    }
+    fn format(&self) -> Format {
+        Format::TarGz
+    }
+}
+impl Archiver for  TarBz2Archiver {
+    fn perform(&self, inout: InOut) -> Result<(), String> {
+        Err("not implement yet".to_string())
+    }
+    fn format(&self) -> Format {
+        Format::TarBz2
+    }
+}
+impl Archiver for  RarArchiver {
+    fn perform(&self, inout: InOut) -> Result<(), String> {
+        Err("not implement yet".to_string())
+    }
+    fn format(&self) -> Format {
+        Format::Rar
+    }
+}
+
+pub fn create_archiver(dest: PathBuf) -> Result<Box<dyn Archiver>, String> {
+    let format = find_format(dest.file_name());
+    match format {
+        Ok(format) => {
+            return match format {
+                Format::Zip => Ok(Box::new(ZipArchiver{})),
+                Format::Tar => Ok(Box::new(TarArchiver{})),
+                Format::TarGz => Ok(Box::new(TarGzArchiver{})),
+                Format::TarBz2 => Ok(Box::new(TarBz2Archiver{})),
+                Format::Rar => Ok(Box::new(RarArchiver{})),
+                _ => Err("unsupported format".to_string()),
+            }
+        }
+        Err(msg) => Err(msg),
+    }
+}
+
+pub fn archiver_info(archiver: Box<dyn Archiver>, inout: InOut) -> String {
+    format!(
+        "Format: {:?}\nDestination: {:?}\nTargets: {:?}",
+        archiver.format(),
+        inout.destination(),
+        inout.targets().iter()
+            .map(|item| item.to_str().unwrap())
+            .collect::<Vec<_>>().join(", ")
+    )
+}
+
+pub struct InOut {
+    dest: PathBuf,
+    targets: Vec<PathBuf>,
+}
+
+impl InOut {
+    pub fn new(dest: PathBuf, targets: Vec<PathBuf>) -> Self {
+        InOut { dest, targets }
+    }
+    pub fn targets(&self) -> Vec<PathBuf> {
+        self.targets.clone()
+    }
+    pub fn destination(&self) -> &PathBuf {
+        &self.dest
+    }
+}
+
+fn find_format(file_name: Option<&OsStr>) -> Result<Format, String> {
+    match file_name {
+        Some(file_name) => {
+            let name = file_name.to_str().unwrap().to_lowercase();
+            if name.ends_with(".tar.gz") || name.ends_with(".tgz") {
+                return Ok(Format::TarGz);
+            } else if name.ends_with(".tar.bz2") || name.ends_with(".tbz2") {
+                return Ok(Format::TarBz2);
+            } else if name.ends_with(".tar") {
+                return Ok(Format::Tar);
+            } else if name.ends_with(".rar") {
+                return Ok(Format::Rar);
+            } else if name.ends_with(".zip") {
+                return Ok(Format::Zip);
+            } else {
+                return Ok(Format::Unknown);
+            }
+        }
+        None => Err("no file name provided".to_string()),
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub enum Format {
+    Zip,
+    Tar,
+    TarGz,
+    TarBz2,
+    Rar,
+    Unknown,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_format() {
+        assert!(find_format(None).is_err());
+        assert_eq!(find_format(Some(OsStr::new("hoge.zip"))), Ok(Format::Zip));
+        assert_eq!(find_format(Some(OsStr::new("hoge.unknown"))), Ok(Format::Unknown));
+        assert_eq!(find_format(Some(OsStr::new("hoge.tar"))), Ok(Format::Tar));
+        assert_eq!(find_format(Some(OsStr::new("hoge.rar"))), Ok(Format::Rar));
+        assert_eq!(find_format(Some(OsStr::new("hoge.tar.gz"))), Ok(Format::TarGz));
+        assert_eq!(find_format(Some(OsStr::new("hoge.tar.bz2"))), Ok(Format::TarBz2));
+    }
+}
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 0a8481a..896f7b7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,5 @@
-use std::path::PathBuf;
 use clap::Parser;
-use cli::{RunMode, CliOpts};
+use cli::CliOpts;
 
 mod cli;
 
@@ -10,6 +9,8 @@ fn main() {
 
 #[cfg(test)]
 mod tests {
+    use std::path::PathBuf;
+    use cli::RunMode;
     use super::*;
 
     #[test]