diff --git a/contributing.md b/contributing.md
new file mode 100644
index 0000000..d022a0f
--- /dev/null
+++ b/contributing.md
@@ -0,0 +1,9 @@
+```bash
+cargo fmt
+```
+
+```bash
+rustup component add clippy
+
+cargo clippy
+```
diff --git a/src/main.rs b/src/main.rs
index 59125e5..2f99416 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,4 @@
+#![allow(clippy::collapsible_if)]
 extern crate libc;
 extern crate pretty_bytes;
 
@@ -66,10 +67,9 @@ pub struct Cli {
   time_format: String,
 }
 
-fn main() -> Result<(), Box<dyn std::error::Error>> {
+fn output() -> Result<(), Box<dyn std::error::Error>> {
   let args = Cli::from_args();
   let directory = &args.path;
-  let headline_on = &args.headline_on;
   let hidden_files = &args.hidden_files;
   let wide_mode = &args.wide_mode;
   let time_on = &args.time_on;
@@ -81,52 +81,44 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
   let time_format = &args.time_format;
   let colors_on = &args.colors_on;
 
-  draw_headlines(
-    *headline_on,
-    *perms_on,
-    *size_on,
-    *time_on,
-    *group_on,
-    *user_on,
-  );
-
   let mut singly_found = false;
   if !std::path::Path::new(directory).exists() {
     let entries = fs::read_dir(".")?
       .map(|res| res.map(|e| e.path()))
       .collect::<Result<Vec<_>, io::Error>>()?;
-      
-      let mut size_count = 4;
-      for s in &entries { 
-        if convert(fs::symlink_metadata(&s)?.size() as f64).len() > size_count {
-          size_count = convert(fs::symlink_metadata(&s)?.size() as f64).len();
-        };
+
+    let mut size_count = 4;
+    for s in &entries {
+      if convert(fs::symlink_metadata(&s)?.size() as f64).len() > size_count {
+        size_count = convert(fs::symlink_metadata(&s)?.size() as f64).len();
+      };
+    }
+    for e in &entries {
+      if e
+        .file_name()
+        .unwrap()
+        .to_str()
+        .unwrap()
+        .to_lowercase()
+        .contains(&args.path.display().to_string().to_lowercase())
+      {
+        let _ = single(e, size_count, *wide_mode, time_format);
+        singly_found = true;
       }
-        for e in &entries {
-          if e
-            .file_name()
-              .unwrap()
-              .to_str()
-              .unwrap()
-              .to_lowercase()
-              .contains(&args.path.display().to_string().to_lowercase())
-          {
-            let _ = single(e, size_count, *wide_mode, time_format);
-            singly_found = true;
-          }
-        }
-        if !singly_found {
-          if !*colors_on {
-            print!("{}", color::Fg(color::Red));
-          }
-          println!(
-            "{}",
-            Style::new()
-            .bold()
-            .paint(format!("{} could not be found", &args.path.display().to_string()))
-          );
-        }
-        std::process::exit(1);
+    }
+    if !singly_found {
+      if !*colors_on {
+        print!("{}", color::Fg(color::Red));
+      }
+      println!(
+        "{}",
+        Style::new().bold().paint(format!(
+          "{} could not be found",
+          &args.path.display().to_string()
+        ))
+      );
+    }
+    std::process::exit(1);
   }
 
   if !directory.symlink_metadata()?.is_dir() {
@@ -134,61 +126,64 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     std::process::exit(0);
   }
 
-
   let entries = fs::read_dir(directory)?
     .map(|res| res.map(|e| e.path()))
     .collect::<Result<Vec<_>, io::Error>>()?;
 
-    let mut size_count = 4;
-    let mut group_size = 8;
-    for s in &entries {
-      if convert(fs::symlink_metadata(&s)?.size() as f64).len() > size_count {
-        size_count = convert(fs::symlink_metadata(&s)?.size() as f64).len();
-      };
-
-      let metadata_uid = fs::symlink_metadata(&s)?.uid();
-      let user_name_len = get_user_name(metadata_uid).len();
-      if user_name_len > group_size {
-        group_size = user_name_len;
-      }
+  let mut size_count = 4;
+  let mut group_size = 8;
+  for s in &entries {
+    if convert(fs::symlink_metadata(&s)?.size() as f64).len() > size_count {
+      size_count = convert(fs::symlink_metadata(&s)?.size() as f64).len();
+    };
+
+    let metadata_uid = fs::symlink_metadata(&s)?.uid();
+    let user_name_len = get_user_name(metadata_uid).len();
+    if user_name_len > group_size {
+      group_size = user_name_len;
     }
+  }
 
-    let mut dirs: Vec<&std::path::PathBuf> = vec![];
-
-    for e in &entries {
-      if !&e.file_name().unwrap().to_str().unwrap().starts_with(".") || *hidden_files {
-        if *&e.is_file() && !*is_sorted {
-          dirs.push(*&e);
-        } else {
-          if !perms_on {
-            let _ = file_perms(&e);
-          }
+  let mut dirs: Vec<&std::path::PathBuf> = vec![];
 
-          if !size_on {
-            let _ = file_size(size_count, &e);
-          }
+  for e in &entries {
+    if !&e.file_name().unwrap().to_str().unwrap().starts_with('.') || *hidden_files {
+      if e.is_file() && !*is_sorted {
+        dirs.push(e);
+      } else {
+        if !perms_on {
+          let _ = file_perms(&e);
+        }
 
-          if !time_on {
-            let _ = time_mod(e, time_format);
-          }
+        if !size_on {
+          let _ = file_size(size_count, &e);
+        }
 
-          if !group_on {
-            let _ = show_group_name(e);
-          }
+        if !time_on {
+          let _ = time_mod(e, time_format);
+        }
 
-          if !user_on {
-            let _ = show_user_name(e);
-          }
+        if !group_on {
+          let _ = show_group_name(e);
+        }
 
-          let _ = show_file_name(&e, *wide_mode);
+        if !user_on {
+          let _ = show_user_name(e);
         }
+
+        let _ = show_file_name(&e, *wide_mode);
       }
     }
-    for e in &dirs {
-      let _ = single(e, size_count, *wide_mode, time_format);
-    }
+  }
+  for e in &dirs {
+    let _ = single(e, size_count, *wide_mode, time_format);
+  }
 
-    Ok(())
+  Ok(())
+}
+
+fn main() {
+  let _ = output();
 }
 
 pub fn draw_headlines(
@@ -216,7 +211,7 @@ pub fn draw_headlines(
       draw_headline("user", 0, true);
     }
     draw_headline("name", 0, true);
-    print!("\n");
+    println!();
   }
 }
 
@@ -244,8 +239,8 @@ pub fn file_size(
   print!(
     "{} ",
     Style::new()
-    .bold()
-    .paint(convert(fs::symlink_metadata(&e)?.size() as f64))
+      .bold()
+      .paint(convert(fs::symlink_metadata(&e)?.size() as f64))
   );
   Ok(())
 }
@@ -254,7 +249,7 @@ pub fn time_mod(
   e: &std::path::PathBuf,
   time_format: &str,
 ) -> Result<(), Box<dyn std::error::Error>> {
-  if let Ok(_) = e.symlink_metadata()?.modified() {
+  if e.symlink_metadata()?.modified().is_ok() {
     let mtime = FileTime::from_last_modification_time(&e.symlink_metadata().unwrap());
     let d = NaiveDateTime::from_timestamp(mtime.seconds() as i64, 0);
     if !Cli::from_args().colors_on {
@@ -277,7 +272,7 @@ pub fn show_group_name(e: &std::path::PathBuf) -> Result<(), Box<dyn std::error:
       match get_group_by_gid(fs::symlink_metadata(e)?.gid()).as_ref() {
         Some(n) => n.name().to_str().unwrap(),
         None => "",
-  }
+      }
     )
   );
   Ok(())
@@ -293,7 +288,7 @@ pub fn show_user_name(e: &std::path::PathBuf) -> Result<(), Box<dyn std::error::
       match get_user_by_uid(fs::symlink_metadata(e)?.uid()).as_ref() {
         Some(n) => n.name().to_str().unwrap(),
         None => "",
-  }
+      }
     )
   );
   Ok(())
@@ -313,7 +308,7 @@ pub fn show_file_name(
     }
     print!("{}/", &e.file_name().unwrap().to_str().unwrap());
     if !wide_mode {
-      print!("\n");
+      println!();
     } else {
       print!(" ");
     }
@@ -324,8 +319,8 @@ pub fn show_file_name(
     print!(
       "{} -> ",
       Style::new()
-      .bold()
-      .paint(e.file_name().unwrap().to_str().unwrap())
+        .bold()
+        .paint(e.file_name().unwrap().to_str().unwrap())
     );
     match fs::canonicalize(fs::read_link(e)?) {
       Ok(_n) => {
@@ -335,9 +330,9 @@ pub fn show_file_name(
             print!(
               "{}/",
               fs::canonicalize(fs::read_link(e)?)
-              .unwrap()
-              .to_str()
-              .unwrap()
+                .unwrap()
+                .to_str()
+                .unwrap()
             )
           }
         } else {
@@ -346,9 +341,9 @@ pub fn show_file_name(
             print!(
               "{}",
               fs::canonicalize(fs::read_link(e)?)
-              .unwrap()
-              .to_str()
-              .unwrap()
+                .unwrap()
+                .to_str()
+                .unwrap()
             )
           }
         }
@@ -374,7 +369,7 @@ pub fn show_file_name(
       }
     }
     if !wide_mode {
-      print!("\n");
+      println!();
     } else {
       print!(" ");
     }
@@ -385,11 +380,11 @@ pub fn show_file_name(
     print!(
       "{}",
       Style::new()
-      .bold()
-      .paint(e.file_name().unwrap().to_str().unwrap())
+        .bold()
+        .paint(e.file_name().unwrap().to_str().unwrap())
     );
     if !wide_mode {
-      print!("\n");
+      println!();
     } else {
       print!(" ");
     }
@@ -461,7 +456,7 @@ pub fn perms(mode: u16) -> String {
       format!("{}{}", color::Fg(color::LightRed), group),
       format!("{}{}", color::Fg(color::Yellow), other),
     ]
-      .join("")
+    .join("")
   } else {
     [user, group, other].join("")
   }