Add backspace functionality (without displaying) and echo command

src/task/keyboard.rs

@@ -1,9 +1,10 @@
 use conquer_once::spin::OnceCell;
 use crossbeam_queue::ArrayQueue;
 use crate::println;
-use crate::serial_print;
+use crate::{serial_print, serial_println};
 use alloc::string::String;
 use crate::alloc::string::ToString;
+use alloc::vec::Vec;
 
 use pc_keyboard::KeyCode;
 
@@ -95,15 +96,21 @@ pub async fn return_keychar() {
 	     if let Some(key) = keyboard.process_keyevent(key_event) {
 	     match key {   
                 DecodedKey::Unicode(character) => (
-					       if scancode == 28 { // 28 is keycode for Enter key
+					       match scancode {	  
+					       28 => { // 28 is keycode for Enter key
 					       	  println!();
 						  command_func(command);
 						  command = "".to_string();
 						  print!("> ");
-						} else {
+						}
+						14 => { // 14 is keycode for Backspace key
+						  command.pop();
+						}
+						scancode => {
 						  print!("{}", character);
 						  command.push(character);
 						}
+					}
 		),
                 DecodedKey::RawKey(key) => serial_print!("{:?}", key),
 	     };
@@ -112,7 +119,18 @@ pub async fn return_keychar() {
 	}
 }
 
-fn command_func(command: String) {
+fn command_func(input_command: String) {
+   let mut command = String::new();
+   let mut args = String::new();
+   let mut command_vec: Vec<&str> = input_command.split(" ").collect();
+   command = command_vec[0].to_string();
+   command_vec.remove(0);
+   for i in command_vec {
+       for j in i.chars() {
+       	   args.push(j);
+	  }
+       args.push(' ');
+   }
    match command.as_str() {
    	 "hi" => {
 	 		  println!("hello command!!!");
@@ -120,6 +138,9 @@ fn command_func(command: String) {
 	 "wow" => {
 			  println!("wow!!");
 			  }
+	"echo" => {
+	       	  println!("{} ", args);
+	}
 	command => {
 		println!("{}: command not found", command);
 		}