diff --git a/config/default.toml b/config/default.toml
index 2a585b7..f85443a 100644
--- a/config/default.toml
+++ b/config/default.toml
@@ -1,10 +1,12 @@
 [colortheme]
 background = [0x26, 0x26, 0x28]
 command-bar = [0x20, 0x28, 0x20]
-cmdbar-prompt = [0x40, 0x40, 0x40]
+cmdbar-prompt = [0x60, 0x60, 0x60]
 cmdbar-cmdexist = [0x40, 0xff, 0x40]
 cmdbar-cmdunexist = [0xff, 0x40, 0x40]
 
 [command]
 new-window = "n"
 quit = "q"
+abcdefg = "abcd"
+fdsafdsa = "fdsa"
diff --git a/src/api.rs b/src/api.rs
new file mode 100644
index 0000000..c0f55a0
--- /dev/null
+++ b/src/api.rs
@@ -0,0 +1,5 @@
+use crate::window::Window;
+
+pub fn new_window() -> Box<dyn Window> {
+    todo!()
+}
diff --git a/src/api.rs~ b/src/api.rs~
new file mode 100644
index 0000000..5bdb5b1
--- /dev/null
+++ b/src/api.rs~
@@ -0,0 +1,7 @@
+use std::collection::HashMap;
+
+use crate::window::Window;
+
+pub fn new_window() -> Box<dyn Window> {
+    todo!()
+}
diff --git a/src/application.rs b/src/application.rs
index 68a7f71..31fc466 100644
--- a/src/application.rs
+++ b/src/application.rs
@@ -1,14 +1,13 @@
 use std::{
     collections::HashMap,
     io::{self, stdout, Stdout, Write},
+    sync::mpsc,
     thread,
     time::Duration,
 };
 
 use crossterm::{
-    cursor,
-    event::{self, KeyEvent, KeyModifiers},
-    queue,
+    cursor, event, queue,
     style::{self, Color},
     terminal::{self, disable_raw_mode, enable_raw_mode, ClearType},
 };
@@ -16,7 +15,7 @@ use crossterm::{
 use unicode_width::UnicodeWidthStr;
 
 use crate::{
-    colortheme::ColorTheme, command::CommandProcessor, iterate_config, window::Window, Config,
+    colortheme::ColorTheme, command::CommandProcessor, innerpipe::PipeObj, window::Window, Config,
 };
 
 pub struct Application {
@@ -24,7 +23,7 @@ pub struct Application {
     colortheme: ColorTheme,
     stdout: Stdout,
     size: (u16, u16),
-    windows: HashMap<usize, Window>,
+    windows: HashMap<usize, Box<dyn Window>>,
     cmdprocessor: CommandProcessor,
 }
 
@@ -79,7 +78,15 @@ impl Application {
 
     fn command_process(&mut self) -> bool {
         if let toml::Value::Table(map) = &self.config.get("command").unwrap() {
-            if self.cmdprocessor.process(map) {
+            let (tx, rx) = mpsc::channel();
+            if self.cmdprocessor.process(map, tx) {
+                while let Ok(pipeobj) = rx.recv() {
+                    match pipeobj {
+                        PipeObj::NewWindow(win) => {
+                            self.windows.insert(win.get_id(), win);
+                        }
+                    }
+                }
                 true
             } else {
                 false
@@ -98,7 +105,15 @@ impl Application {
             }
         }
         let x = UnicodeWidthStr::width(show.as_str()) as u16;
-        let mut prompt = String::new();
+	let mut suggestion = String::new();
+	for c in self.cmdprocessor.get_suggestion().chars() {
+	    suggestion.push(c);
+	    if UnicodeWidthStr::width(suggestion.as_str()) as u16 >= self.size.0 - 1 - x {
+		break;
+	    }
+	}
+	let x = x + UnicodeWidthStr::width(suggestion.as_str()) as u16;
+        let mut prompt = String::from(if x == 0 {""}else{" - "});
         for c in self.cmdprocessor.get_prompt().chars() {
             prompt.push(c);
             if UnicodeWidthStr::width(prompt.as_str()) as u16 >= self.size.0 - 1 - x {
@@ -116,8 +131,9 @@ impl Application {
                 self.colortheme.cmdbar_cmdexist
             }),
             style::Print(show),
-            cursor::SavePosition,
-            style::SetForegroundColor(self.colortheme.cmdbar_prompt),
+	    cursor::SavePosition,
+	    style::SetForegroundColor(self.colortheme.cmdbar_prompt),
+	    style::Print(suggestion),
             style::Print(prompt),
             style::Print(" ".repeat((self.size.0 - x) as usize)),
             cursor::RestorePosition,
diff --git a/src/command.rs b/src/command.rs
index 9ba3a02..4f4db67 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -1,6 +1,8 @@
+use std::sync::mpsc::Sender;
+
 use crossterm::event::{self, KeyEvent, KeyModifiers};
 
-use crate::{iterate_config, Config};
+use crate::{api, innerpipe::PipeObj, iterate_config, Config};
 
 pub struct CommandProcessor {
     command_mode: bool,
@@ -8,6 +10,7 @@ pub struct CommandProcessor {
     unknown_cmd: bool,
     cmdbar_show: String,
     cmdbar_prompt: String,
+    cmdbar_suggestion: String,
 }
 
 impl CommandProcessor {
@@ -18,6 +21,7 @@ impl CommandProcessor {
             unknown_cmd: false,
             cmdbar_show: String::new(),
             cmdbar_prompt: String::from("New workspace"),
+            cmdbar_suggestion: String::new(),
         }
     }
 
@@ -29,6 +33,10 @@ impl CommandProcessor {
         &self.cmdbar_prompt
     }
 
+    pub fn get_suggestion(&self) -> &String {
+	&self.cmdbar_suggestion
+    }
+
     pub fn unknown(&self) -> bool {
         self.unknown_cmd
     }
@@ -37,24 +45,39 @@ impl CommandProcessor {
         self.command_mode
     }
 
-    pub fn process(&mut self, map: &Config) -> bool {
-        let f = |_, value| {
-            if let &toml::Value::String(ref s) = value {
-                s == &self.command
+    pub fn process(&mut self, map: &Config, sender: Sender<PipeObj>) -> bool {
+        if let Some((name, cmd, full)) = iterate_config(map, &self.command) {
+            self.cmdbar_prompt = format!("{}", name);
+            if !full {
+                let mut s = cmd.as_str().unwrap().to_string();
+                for _ in self.command.chars() {
+                    s.remove(0);
+                }
+		if self.command.is_empty() {
+		    self.cmdbar_suggestion.clear();
+		} else {
+                    self.cmdbar_suggestion = s;
+		}
             } else {
-                false
-            }
-        };
-        if let Some((name, _)) = iterate_config(map, &f) {
-            self.command.clear();
-            self.cmdbar_prompt = format!(" - {}", name);
-            self.unknown_cmd = false;
-            match name.as_str() {
-                "quit" => return true,
-                _ => (),
+		self.cmdbar_suggestion.clear();
+	    }
+	    self.unknown_cmd = false;
+	    if full {
+		self.command.clear();
+                match name.as_str() {
+                    "quit" => return true,
+                    "new-window" => {
+                        let win = api::new_window();
+                        sender.send(PipeObj::NewWindow(win)).unwrap();
+                    }
+                    "abcd" => (),
+                    "dfas" => (),
+                    _ => (),
+                }
             }
         } else if !self.cmdbar_show.is_empty() {
-            self.cmdbar_prompt = String::from(" | Unknown command");
+            self.cmdbar_prompt = String::from("Unknown command");
+	    self.cmdbar_suggestion.clear();
             self.unknown_cmd = true;
         } else {
             self.cmdbar_prompt.clear();
diff --git a/src/innerpipe.rs b/src/innerpipe.rs
new file mode 100644
index 0000000..3f1fdb3
--- /dev/null
+++ b/src/innerpipe.rs
@@ -0,0 +1,5 @@
+use crate::window::Window;
+
+pub enum PipeObj {
+    NewWindow(Box<dyn Window>),
+}
diff --git a/src/innerpipe.rs~ b/src/innerpipe.rs~
new file mode 100644
index 0000000..e0d35c5
--- /dev/null
+++ b/src/innerpipe.rs~
@@ -0,0 +1,3 @@
+pub enum PipeObj {
+    NewWindow(Box<dyn Window>),
+}
diff --git a/src/lib.rs b/src/lib.rs
index 3413406..01f6579 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,9 @@
+pub mod api;
 pub mod application;
 pub mod colortheme;
-pub mod window;
 pub mod command;
+pub mod innerpipe;
+pub mod window;
 
 use std::io;
 
@@ -10,17 +12,19 @@ use toml::map::Map;
 
 pub type Config = Map<String, toml::Value>;
 
-pub fn iterate_config<'a, 'b: 'a, F>(config: &'b Config, f: &F) -> Option<(String, toml::Value)>
-where
-    F: Fn(&'a str, &'b toml::Value) -> bool,
-{
+pub fn iterate_config<'a, 'b: 'a>(
+    config: &'b Config,
+    cmd: &'a str,
+) -> Option<(String, toml::Value, bool)> {
     for (name, value) in config {
         if let toml::Value::Table(map) = value {
-            if let Some(p) = iterate_config(map, f) {
+            if let Some(p) = iterate_config(map, cmd) {
                 return Some(p);
             }
-        } else if f(name, value) {
-            return Some((name.clone(), value.clone()));
+        } else if cmd == value.as_str().unwrap() {
+            return Some((name.clone(), value.clone(), true));
+        } else if value.as_str().unwrap().starts_with(cmd) {
+            return Some((name.clone(), value.clone(), false));
         }
     }
     None
diff --git a/src/window.rs b/src/window.rs
index a95ddd3..dfb2b0b 100644
--- a/src/window.rs
+++ b/src/window.rs
@@ -1,4 +1,9 @@
-pub struct Window {
-    pos: (u16, u16),
-    size: (u16, u16),
+use std::io;
+
+pub trait Window {
+    fn get_pos(&self) -> (u16, u16);
+    fn get_size(&self) -> (u16, u16);
+    fn get_id(&self) -> usize;
+
+    fn render(&mut self, screen_size: (u16, u16)) -> io::Result<()>;
 }