simplify user 'sh' with alloc

user/rcore-ulib/src/io.rs

@@ -1,9 +1,11 @@
+use alloc::string::String;
 use core::fmt::{self, Write};
 use core::option::Option;
-use crate::syscall::{sys_write, sys_read, sys_putc};
 
-pub const STDIN: usize=0;
-pub const STDOUT: usize=1;
+use crate::syscall::{sys_putc, sys_read, sys_write};
+
+pub const STDIN: usize = 0;
+pub const STDOUT: usize = 1;
 
 #[macro_export]
 macro_rules! print {
@@ -26,22 +28,51 @@ pub fn print_putc(args: fmt::Arguments) {
     SysPutc.write_fmt(args).unwrap();
 }
 
-pub fn getc() -> Option<u8>{
-	use core::mem::uninitialized;
-	let mut c:[u8;1] = unsafe { uninitialized() };
-	let ret=sys_read(STDIN,c.as_mut_ptr(),1);
-	match ret {
-		1 => Some(c[0]),
-		0 => None,
-		_ => panic!(),
-	}
+pub fn getc() -> Option<u8> {
+    let mut c = 0u8;
+    let ret = sys_read(STDIN, &mut c, 1);
+    match ret {
+        1 => Some(c),
+        0 => None,
+        _ => panic!(),
+    }
 }
 
-pub fn putc(c:u8){
-	sys_putc(c);
+pub fn get_line() -> String {
+    let mut s = String::new();
+    loop {
+        let ret = getc();
+        match ret {
+            None => return s,
+            Some(byte) => {
+                let c = byte as char;
+                match c {
+                    '\x08' | '\x7f' /* '\b' */ => {
+                        if s.pop().is_some() {
+                            print!("\x08 \x08");
+                        }
+                    }
+                    ' '...'\x7e' => {
+                        s.push(c);
+                        print!("{}", c);
+                    }
+                    '\n' | '\r' => {
+                        print!("\n");
+                        return s;
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+}
+
+pub fn putc(c: u8) {
+    sys_putc(c);
 }
 
 struct StdOut;
+
 struct SysPutc;
 
 impl fmt::Write for StdOut {

user/rcore-ulib/src/lib.rs

@@ -1,10 +1,13 @@
 #![no_std]
 #![feature(asm)]
+#![feature(alloc)]
 #![feature(lang_items)]
 #![feature(panic_info_message)]
 #![feature(linkage)]
 #![feature(compiler_builtins_lib)]
 
+extern crate alloc;
+
 #[macro_use]
 pub mod io;
 pub mod syscall;

user/src/bin/sh.rs

@@ -1,115 +1,39 @@
 #![no_std]
 #![no_main]
+#![feature(alloc)]
 
+extern crate alloc;
 #[macro_use]
 extern crate rcore_ulib;
-use rcore_ulib::io::getc;
-use rcore_ulib::syscall::{sys_exec, sys_fork, sys_wait};
 
-pub fn get_line(buffer: &mut [u8]) -> usize {
-    let mut pos: usize = 0;
-    loop {
-        let ret = getc();
-        match ret {
-            None => break,
-            Some(byte) => {
-                let c = byte as char;
-                match c {
-					'\u{8}' /* '\b' */ => {
-						if pos > 0 {
-                    		print!("\u{8} \u{8}");
-							pos-=1;
-						}
-					}
-					' '...'\u{7e}' => {
-						if pos<buffer.len() {
-							buffer[pos]=byte;
-						}
-						pos+=1;
-						print!("{}", c);
-					}
-					'\n' | '\r' => {
-						print!("\n");
-						break;
-					}
-					_ => {}
-				}
-            }
-        }
-    }
-    pos
-}
+use alloc::vec::Vec;
 
-const BUFFER_SIZE: usize = 4096;
+use rcore_ulib::io::get_line;
+use rcore_ulib::syscall::{sys_exec, sys_fork, sys_wait};
 
 // IMPORTANT: Must define main() like this
 #[no_mangle]
 pub fn main() -> i32 {
-    use core::mem::uninitialized;
-    let mut buf: [u8; BUFFER_SIZE] = unsafe { uninitialized() };
     println!("Rust user shell");
     loop {
         print!(">> ");
-        let len = get_line(&mut buf);
-        if len > BUFFER_SIZE {
-            println!("Command is too long!");
+        let cmd = get_line();
+        // split cmd, make argc & argv
+        let cmd = cmd.replace(' ', "\0") + "\0";
+        let ptrs: Vec<*const u8> = cmd.split('\0')
+            .filter(|s| !s.is_empty()).map(|s| s.as_ptr()).collect();
+        if ptrs.is_empty() {
+            continue;
+        }
+
+        let pid = sys_fork();
+        assert!(pid >= 0);
+        if pid == 0 {
+            return sys_exec(ptrs[0], ptrs.len(), ptrs.as_ptr());
         } else {
-            let cmd = &buf[..len];
-            let mut parsed: [u8; BUFFER_SIZE + 1] = unsafe { uninitialized() };
-            let mut offset: [usize; BUFFER_SIZE + 1] = unsafe { uninitialized() };
-            let mut start: usize = 0;
-            let mut pos: usize = 0;
-            let mut is_word = false;
-            let mut parsed_pos: usize = 0;
-            let mut offset_pos: usize = 0;
-            loop {
-                if pos >= cmd.len() {
-                    if is_word {
-                        offset[offset_pos] = parsed_pos;
-                        offset_pos += 1;
-                        parsed[parsed_pos..parsed_pos + pos - start]
-                            .copy_from_slice(&cmd[start..pos]);
-                        parsed_pos += pos - start;
-                        parsed[parsed_pos] = 0;
-                        // parsed_pos+=1;
-                    }
-                    break;
-                }
-                if cmd[pos] == (' ' as u8) {
-                    if is_word {
-                        is_word = false;
-                        offset[offset_pos] = parsed_pos;
-                        offset_pos += 1;
-                        parsed[parsed_pos..parsed_pos + pos - start]
-                            .copy_from_slice(&cmd[start..pos]);
-                        parsed_pos += pos - start;
-                        parsed[parsed_pos] = 0;
-                        parsed_pos += 1;
-                    }
-                } else {
-                    if !is_word {
-                        is_word = true;
-                        start = pos;
-                    }
-                }
-                pos += 1;
-            }
-            if offset_pos > 0 {
-                let pid = sys_fork();
-                if pid == 0 {
-                    let mut ptrs: [*const u8; BUFFER_SIZE] = unsafe { uninitialized() };
-                    for i in 0..offset_pos {
-                        ptrs[i] = unsafe { parsed.as_ptr().offset(offset[i] as isize) };
-                    }
-                    return sys_exec(parsed.as_ptr(), offset_pos, ptrs.as_ptr());
-                } else if pid < 0 {
-                    panic!("pid<0")
-                } else {
-                    let mut code: i32 = unsafe { uninitialized() };
-                    sys_wait(pid as usize, &mut code as *mut i32);
-                    println!("\n[Process exited with code {}]", code);
-                }
-            }
+            let mut code: i32 = 0;
+            sys_wait(pid as usize, &mut code);
+            println!("\n[Process exited with code {}]", code);
         }
     }
 }