vfs: add is_terminal()

kernel/libk/src/vfs/file/device.rs

@@ -93,12 +93,6 @@ impl CharFile {
             self.device.0.read_nonblocking(buf)
         }
     }
-    //     if self.read {
-    //         self.device.0.read(buf)
-    //     } else {
-    //         Err(Error::InvalidOperation)
-    //     }
-    // }
 
     pub fn write(&self, buf: &[u8]) -> Result<usize, Error> {
         if !self.write {
@@ -111,10 +105,8 @@ impl CharFile {
             self.device.0.write_nonblocking(buf)
         }
     }
-    //     if self.write {
-    //         self.device.0.write(buf)
-    //     } else {
-    //         Err(Error::ReadOnly)
-    //     }
-    // }
+
+    pub fn is_terminal(&self) -> bool {
+        self.device.0.is_terminal()
+    }
 }

kernel/libk/src/vfs/file/mod.rs

@@ -341,6 +341,14 @@ impl File {
 
     /// Performs a device-specific request
     pub fn device_request(&self, req: &mut DeviceRequest) -> Result<(), Error> {
+        match req {
+            DeviceRequest::IsTerminal(value) => {
+                *value = self.is_terminal();
+                return Ok(());
+            }
+            _ => (),
+        }
+
         match self {
             Self::Char(f) => f.device.device_request(req),
             Self::Block(f) => f.device.device_request(req),
@@ -375,6 +383,14 @@ impl File {
             _ => Err(Error::InvalidOperation),
         }
     }
+
+    pub fn is_terminal(&self) -> bool {
+        match self {
+            Self::Char(dev) => dev.is_terminal(),
+            Self::PtySlave(_) | Self::PtyMaster(_) => true,
+            _ => false,
+        }
+    }
 }
 
 impl PageProvider for File {

lib/abi/src/io/device.rs

@@ -29,6 +29,8 @@ pub enum DeviceRequest {
     GetTerminalSize(MaybeUninit<terminal::TerminalSize>),
     /// Sets a foreground process group ID for the terminal
     SetTerminalGroup(ProcessGroupId),
+    /// Returns `true` if a file/device is a terminal
+    IsTerminal(bool),
 
     /// "Acquires" ownership of the device, preventing others from accessing it
     AcquireDevice,

lib/runtime/src/io.rs

@@ -28,7 +28,7 @@ pub use abi::io::{
     FileType, OpenOptions, PipeOptions, RawFd, SeekFrom, TimerOptions,
 };
 
-use abi::{error::Error, process::ProcessOption, util::FixedString};
+use abi::{error::Error, io::DeviceRequest, process::ProcessOption, util::FixedString};
 use alloc::string::String;
 
 pub fn current_directory<T, F: FnOnce(&str) -> T>(mapper: F) -> Result<T, Error> {
@@ -50,3 +50,12 @@ pub fn set_current_directory(path: &str) -> Result<(), Error> {
     unsafe { crate::sys::set_process_option(&mut option) }?;
     Ok(())
 }
+
+pub fn is_terminal(f: RawFd) -> bool {
+    let mut option = DeviceRequest::IsTerminal(false);
+    let res = unsafe { crate::sys::device_request(f, &mut option) };
+    match (res, option) {
+        (Ok(()), DeviceRequest::IsTerminal(true)) => true,
+        _ => false,
+    }
+}

userspace/lib/libterm/src/input.rs

@@ -1,8 +1,10 @@
 use std::{
     fmt,
-    io::{self, Read, Stdin},
+    io::{self, Read},
 };
 
+use crate::TermInput;
+
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
 pub enum TermKey {
     Char(char),
@@ -23,7 +25,7 @@ pub trait ReadChar {
     fn read_char(&mut self) -> Result<char, InputError>;
 }
 
-impl ReadChar for Stdin {
+impl ReadChar for TermInput {
     fn read_char(&mut self) -> Result<char, InputError> {
         let mut buf = [0; 4];
         self.read_exact(&mut buf[..1])

userspace/lib/libterm/src/lib.rs

@@ -1,9 +1,7 @@
 #![cfg_attr(target_os = "yggdrasil", feature(yggdrasil_os, rustc_private))]
 
 use std::{
-    fmt,
-    io::{self, stdin, stdout, Stdin, Stdout, Write},
-    os::fd::{AsRawFd, RawFd},
+    fmt, fs::File, io::{self, stdin, stdout, IsTerminal, Read, Stdin, Stdout, Write}, os::fd::{AsRawFd, RawFd}
 };
 
 pub use self::{input::ReadChar, sys::RawMode};
@@ -43,8 +41,31 @@ pub trait RawTerminal {
     fn raw_size(&self) -> io::Result<(usize, usize)>;
 }
 
+enum TermInput {
+    Stdin(Stdin),
+    File(File)
+}
+
+impl Read for TermInput {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        match self {
+            Self::Stdin(stdin) => stdin.read(buf),
+            Self::File(file) => file.read(buf)
+        }
+    }
+}
+
+impl AsRawFd for TermInput {
+    fn as_raw_fd(&self) -> RawFd {
+        match self {
+            Self::Stdin(stdin) => stdin.as_raw_fd(),
+            Self::File(file) => file.as_raw_fd(),
+        }
+    }
+}
+
 pub struct Term {
-    stdin: Stdin,
+    stdin: TermInput,
     stdout: Stdout,
     raw: RawMode,
 }
@@ -134,9 +155,8 @@ impl RawTerminal for Stdout {
 }
 
 impl Term {
-    pub fn is_tty() -> bool {
-        // TODO
-        true
+    pub fn stdin_is_tty() -> bool {
+        stdin().is_terminal()
     }
 
     pub fn input_fd(&self) -> RawFd {
@@ -145,6 +165,12 @@ impl Term {
 
     pub fn open() -> Result<Self, Error> {
         let stdin = stdin();
+        let stdin = if stdin.is_terminal() {
+            TermInput::Stdin(stdin)
+        } else {
+            let file = File::open("/dev/tty")?;
+            TermInput::File(file)
+        };
         let mut stdout = stdout();
 
         // Set stdin to raw mode

userspace/lib/libterm/src/yggdrasil.rs

@@ -1,10 +1,10 @@
 use std::{
-    io::{self, Stdin, Stdout},
+    io::{self, Stdout},
     mem::MaybeUninit,
-    os::yggdrasil::io::{
+    os::{fd::AsRawFd, yggdrasil::io::{
         device::{DeviceRequest, FdDeviceRequest},
         terminal::{update_terminal_options, TerminalOptions},
-    },
+    }},
 };
 
 pub struct RawMode(TerminalOptions);
@@ -13,15 +13,15 @@ impl RawMode {
     /// # Safety
     ///
     /// May leave the terminal in broken state, unsafe.
-    pub unsafe fn enter(stdin: &Stdin) -> io::Result<Self> {
-        update_terminal_options(stdin, |_| TerminalOptions::raw_input()).map(RawMode)
+    pub unsafe fn enter<F: AsRawFd>(stdin: &F) -> io::Result<Self> {
+        update_terminal_options(stdin.as_raw_fd(), |_| TerminalOptions::raw_input()).map(RawMode)
     }
 
     /// # Safety
     ///
     /// May leave the terminal in broken state, unsafe.
-    pub unsafe fn leave(&self, stdin: &Stdin) {
-        update_terminal_options(stdin, |_| self.0).ok();
+    pub unsafe fn leave<F: AsRawFd>(&self, stdin: &F) {
+        update_terminal_options(stdin.as_raw_fd(), |_| self.0).ok();
     }
 }
 

userspace/red/src/main.rs

@@ -347,7 +347,7 @@ fn main() {
         return;
     }
 
-    if !Term::is_tty() {
+    if !Term::stdin_is_tty() {
         eprintln!("Not a tty");
         return;
     }

userspace/sysutils/src/view.rs

@@ -1,6 +1,7 @@
 use std::{
     fmt::{self, Write},
     io,
+    process::ExitCode,
 };
 
 use clap::Parser;
@@ -160,9 +161,15 @@ struct Args {
     filename: String,
 }
 
-fn main() -> Result<(), Error> {
+fn main() -> ExitCode {
     // TODO check if running in a terminal
     let args = Args::parse();
     let view = View::open(&args.filename, !args.no_bar).unwrap();
-    view.run()
+    match view.run() {
+        Ok(()) => ExitCode::SUCCESS,
+        Err(error) => {
+            yggdrasil_rt::debug_trace!("view: {error}");
+            ExitCode::FAILURE
+        }
+    }
 }