Add read_line function to userspace lib

Author: sysheap

userspace/src/bin/yash.rs

@@ -2,43 +2,20 @@
 #![no_main]
 
 use alloc::string::{String, ToString};
-use common::syscalls::{sys_execute, sys_exit, sys_print_programs, sys_read_input_wait, sys_wait};
-use userspace::{print, println};
+use common::syscalls::{sys_execute, sys_exit, sys_print_programs, sys_wait};
+use userspace::{print, println, util::read_line};
 
 extern crate alloc;
 extern crate userspace;
 
-const DELETE: u8 = 127;
-
 #[unsafe(no_mangle)]
 fn main() {
     println!();
     println!("### YaSH - Yet another Shell ###");
     println!("Type 'help' for a list of available commands.");
     loop {
         print!("$ ");
-        let mut input = String::new();
-        loop {
-            let result = sys_read_input_wait();
-            match result {
-                b'\r' | b'\n' => {
-                    // Carriage return
-                    println!();
-                    break;
-                }
-                DELETE => {
-                    if input.pop().is_some() {
-                        print!("{}{}{}", 8 as char, ' ', 8 as char);
-                    }
-                }
-                _ => {
-                    assert!(result.is_ascii());
-                    let result = result as char;
-                    input.push(result);
-                    print!("{}", result);
-                }
-            }
-        }
+        let input = read_line();
         // Parse input and execute
         parse_command_and_execute(input);
     }

userspace/src/util.rs

@@ -1,9 +1,43 @@
+extern crate alloc;
+
+use alloc::string::String;
+use common::syscalls::sys_read_input_wait;
 use core::arch::asm;
 
+use crate::{print, println};
+
+const DELETE: u8 = 127;
+
 pub fn wait(cycles: usize) {
     for _ in 0..cycles {
         unsafe {
             asm!("nop");
         }
     }
 }
+
+pub fn read_line() -> String {
+    let mut input = String::new();
+    loop {
+        let result = sys_read_input_wait();
+        match result {
+            b'\r' | b'\n' => {
+                // Carriage return
+                println!();
+                break;
+            }
+            DELETE => {
+                if input.pop().is_some() {
+                    print!("{}{}{}", 8 as char, ' ', 8 as char);
+                }
+            }
+            _ => {
+                assert!(result.is_ascii());
+                let result = result as char;
+                input.push(result);
+                print!("{}", result);
+            }
+        }
+    }
+    input
+}