Fix various issues while reading files (#307)

* Define device file buffer in kernel

* Implement from u8 for Device

* Reading /dev/null result in error

* Reading an empty dir should not result in error

* Print all bytes from reading devices

* Print errors while reading devices

* Handle ^C and ^D when reading /dev/console

* Create pseudo device files for clocks

* Avoid hardcoding ^C and ^D

* Add missing comment

src/api/console.rs

@@ -1,6 +1,8 @@
 use crate::sys;
 use core::fmt;
 
+pub use crate::sys::console::{ETX_KEY, EOT_KEY};
+
 #[derive(Clone, Copy)]
 pub struct Style {
     foreground: Option<usize>,

src/api/fs.rs

@@ -88,8 +88,7 @@ pub fn open_device(path: &str) -> Option<usize> {
 pub fn create_device(path: &str, kind: DeviceType) -> Option<usize> {
     let flags = OpenFlag::Create as usize | OpenFlag::Device as usize;
     if let Some(handle) = syscall::open(path, flags) {
-        let buf = [kind as u8; 1];
-        syscall::write(handle, &buf);
+        syscall::write(handle, &kind.buf());
         return Some(handle);
     }
     None

src/api/prompt.rs

@@ -32,11 +32,11 @@ impl Prompt {
         let mut parser = Parser::new();
         while let Some(c) = io::stdin().read_char() {
             match c {
-                '\x03' => { // End of Text (^C)
+                console::ETX_KEY => { // End of Text (^C)
                     println!();
                     return Some(String::new());
                 },
-                '\x04' => { // End of Transmission (^D)
+                console::EOT_KEY => { // End of Transmission (^D)
                     println!();
                     return None;
                 },

src/sys/console.rs

@@ -91,10 +91,10 @@ pub fn is_raw_enabled() -> bool {
     *RAW.lock()
 }
 
-const ETX_KEY: char = '\x03'; // End of Text
-const EOT_KEY: char = '\x04'; // End of Transmission
-const BS_KEY:  char = '\x08'; // Backspace
-const ESC_KEY: char = '\x1B'; // Escape
+pub const ETX_KEY: char = '\x03'; // End of Text
+pub const EOT_KEY: char = '\x04'; // End of Transmission
+pub const BS_KEY:  char = '\x08'; // Backspace
+pub const ESC_KEY: char = '\x1B'; // Escape
 
 pub fn key_handle(key: char) {
     let mut stdin = STDIN.lock();

src/sys/fs/device.rs

@@ -3,9 +3,12 @@ use super::dir::Dir;
 use super::file::File;
 use super::block::LinkedBlock;
 
+use alloc::vec;
+use alloc::vec::Vec;
 use crate::sys::console::Console;
 use crate::sys::random::Random;
 
+#[derive(PartialEq, Clone, Copy)]
 #[repr(u8)]
 pub enum DeviceType {
     File = 0,
@@ -14,6 +17,16 @@ pub enum DeviceType {
     Null = 3,
 }
 
+impl DeviceType {
+    pub fn buf(self) -> Vec<u8> {
+        if self == DeviceType::Console {
+            vec![self as u8, 0, 0, 0] // 4 bytes
+        } else {
+            vec![self as u8] // 1 byte
+        }
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum Device {
     File(File),
@@ -22,16 +35,18 @@ pub enum Device {
     Null,
 }
 
-impl Device {
-    fn new(i: u8) -> Self {
+impl From<u8> for Device {
+    fn from(i: u8) -> Self {
         match i {
             i if i == DeviceType::Console as u8 => Device::Console(Console::new()),
             i if i == DeviceType::Random as u8 => Device::Random(Random::new()),
             i if i == DeviceType::Null as u8 => Device::Null,
             _ => unimplemented!(),
         }
     }
+}
 
+impl Device {
     pub fn create(pathname: &str) -> Option<Self> {
         let pathname = realpath(pathname);
         let dirname = dirname(&pathname);
@@ -53,7 +68,7 @@ impl Device {
                 if dir_entry.is_device() {
                     let block = LinkedBlock::read(dir_entry.addr());
                     let data = block.data();
-                    return Some(Self::new(data[0]));
+                    return Some(data[0].into());
                 }
             }
         }
@@ -67,7 +82,7 @@ impl FileIO for Device {
             Device::File(io) => io.read(buf),
             Device::Console(io) => io.read(buf),
             Device::Random(io) => io.read(buf),
-            Device::Null => Ok(0),
+            Device::Null => Err(()),
         }
     }
     fn write(&mut self, buf: &[u8]) -> Result<usize, ()> {

src/sys/fs/dir.rs

@@ -242,11 +242,7 @@ impl FileIO for Dir {
                 break;
             }
         }
-        if i > 0 {
-            Ok(i)
-        } else {
-            Err(())
-        }
+        Ok(i)
     }
     fn write(&mut self, _buf: &[u8]) -> Result<usize, ()> {
         Err(())

src/usr/install.rs

@@ -21,6 +21,9 @@ pub fn copy_files(verbose: bool) {
     copy_file("/bin/sleep", include_bytes!("../../dsk/bin/sleep"), verbose);
 
     create_dir("/dev/clk", verbose); // Clocks
+    create_dev("/dev/clk/uptime", DeviceType::File, verbose); // TODO
+    create_dev("/dev/clk/realtime", DeviceType::File, verbose); // TODO
+    create_dev("/dev/rtc", DeviceType::File, verbose); // TODO
     create_dev("/dev/null", DeviceType::Null, verbose);
     create_dev("/dev/random", DeviceType::Random, verbose);
     create_dev("/dev/console", DeviceType::Console, verbose);

src/usr/pow.rs

@@ -1,6 +1,6 @@
 use crate::usr;
 use crate::api::console::Style;
-use crate::api::{io, random};
+use crate::api::{io, random, console};
 use core::fmt;
 use alloc::format;
 use alloc::string::ToString;
@@ -34,7 +34,7 @@ impl Game {
         let mut parser = Parser::new();
         while let Some(c) = io::stdin().read_char() {
             match c {
-                'q' | '\x03' | '\x04' => { // ^C and ^D
+                'q' | console::ETX_KEY | console::EOT_KEY => {
                     return;
                 },
                 c => {

src/usr/read.rs

@@ -1,7 +1,9 @@
 use crate::{api, sys, usr};
+use crate::api::console;
 use crate::api::fs;
 use crate::api::syscall;
 use crate::sys::cmos::CMOS;
+
 use alloc::borrow::ToOwned;
 use alloc::vec::Vec;
 
@@ -18,6 +20,7 @@ pub fn main(args: &[&str]) -> usr::shell::ExitCode {
         path = path.trim_end_matches('/');
     }
 
+    // TODO: Create device drivers for `/dev` and `/net` hardcoded commands
     match path {
         "/dev/rtc" => {
             let rtc = CMOS::new().rtc();
@@ -81,14 +84,33 @@ pub fn main(args: &[&str]) -> usr::shell::ExitCode {
                 } else if info.is_dir() {
                     usr::list::main(args)
                 } else if info.is_device() {
+                    let is_console = info.size() == 4; // TODO: Improve device detection
                     loop {
-                        if let Ok(bytes) = fs::read_to_bytes(path) {
-                            print!("{}", bytes[0] as char);
-                        }
                         if sys::console::end_of_text() {
                             println!();
                             return usr::shell::ExitCode::CommandSuccessful;
                         }
+                        if let Ok(bytes) = fs::read_to_bytes(path) {
+                            if is_console && bytes.len() == 1 {
+                                match bytes[0] as char {
+                                    console::ETX_KEY => {
+                                        println!("^C");
+                                        return usr::shell::ExitCode::CommandSuccessful;
+                                    }
+                                    console::EOT_KEY => {
+                                        println!("^D");
+                                        return usr::shell::ExitCode::CommandSuccessful;
+                                    }
+                                    _ => {}
+                                }
+                            }
+                            for b in bytes {
+                                print!("{}", b as char);
+                            }
+                        } else {
+                            eprintln!("Could not read '{}'", path);
+                            return usr::shell::ExitCode::CommandError;
+                        }
                     }
                 } else {
                     eprintln!("Could not read type of '{}'", path);