Fix console

kernel/src/arch/riscv32/io.rs

@@ -21,7 +21,6 @@ impl Write for SerialPort {
 pub fn getchar() -> char {
     match sbi::console_getchar() as u8 {
         255 => 0,   // null
-        127 => 8,   // back
         c => c,
     } as char
 }

kernel/src/console.rs

@@ -1,64 +1,26 @@
 use core::ops::Deref;
+use alloc::string::String;
+use arch::io::getchar;
 
-pub struct LineBuf {
-    buf: [u8; BUF_SIZE],
-    len: usize,
-}
-
-pub struct LineBufGuard<'a>(&'a str);
-
-const BUF_SIZE: usize = 256;
-
-impl LineBuf {
-    pub const fn new() -> Self {
-        LineBuf {
-            buf: [0; BUF_SIZE],
-            len: 0,
-        }
-    }
-
-    /// Put a char received from serial. Return str if get a line.
-    pub fn push_u8<'a>(&'a mut self, c: u8) -> Option<LineBufGuard<'a>> {
-        use alloc::str;
+pub fn get_line() -> String {
+    let mut s = String::new();
+    loop {
+        let c = getchar();
         match c {
-            b' '...128 if self.len != BUF_SIZE => {
-                self.buf[self.len] = c;
-                self.len += 1;
+            '\u{7f}' /* '\b' */ => {
+                if s.pop().is_some() {
+                    print!("\u{7f}");
+                }
             }
-            8 /* '\b' */ if self.len != 0 => {
-                self.len -= 1;
+            ' '...'\u{7e}' => {
+                s.push(c);
+                print!("{}", c);
             }
-            b'\n' | b'\r' => {
-                let s = str::from_utf8(&self.buf[..self.len]).unwrap();
-                self.len = 0;
-                return Some(LineBufGuard(s));
+            '\n' | '\r' => {
+                print!("\n");
+                return s;
             }
             _ => {}
         }
-        None
-    }
-}
-
-impl<'a> Deref for LineBufGuard<'a> {
-    type Target = str;
-    fn deref(&self) -> &str {
-        self.0
-    }
-}
-
-use alloc::string::String;
-use arch::io::getchar;
-
-pub fn get_line() -> String {
-    let mut buf = LineBuf::new();
-    loop {
-        let mut c = 0;
-        while c == 0 {
-            c = getchar() as u8;
-        }
-        print!("{}", c as char);
-        if let Some(line) = buf.push_u8(c) {
-            return String::from(&*line);
-        }
     }
 }

kernel/src/fs.rs

@@ -23,13 +23,13 @@ pub fn shell() {
 
     let mut buf = Box::new([0; 64 << 12]);
     loop {
+        print!(">> ");
         use console::get_line;
         let name = get_line();
         if name == "" {
             continue;
         }
         if let Ok(file) = root.borrow().lookup(name.as_str()) {
-            println!("Running: {}", name);
             let len = file.borrow().read_at(0, &mut *buf).unwrap();
             process::add_user_process(name, &buf[..len]);
         } else {