implemented 'type' and 'wait' builtins

fixed some tcsetpgrp() misbehavior

fixed not being able to redirect stderr from builtins

src/libsh/guards.rs

@@ -0,0 +1,215 @@
+use std::cell::RefCell;
+use std::collections::HashSet;
+use std::os::fd::{BorrowedFd, RawFd};
+
+use nix::sys::termios::{self, LocalFlags, Termios, tcgetattr, tcsetattr};
+use nix::unistd::isatty;
+use scopeguard::guard;
+
+thread_local! {
+  static ORIG_TERMIOS: RefCell<Option<Termios>> = const { RefCell::new(None) };
+}
+
+use crate::parse::lex::Span;
+use crate::procio::{IoFrame, borrow_fd};
+use crate::readline::term::get_win_size;
+use crate::state::write_vars;
+
+use super::sys::TTY_FILENO;
+
+// ============================================================================
+// ScopeGuard — RAII variable scope management
+// ============================================================================
+
+pub fn scope_guard(args: Option<Vec<(String, Span)>>) -> impl Drop {
+  let argv = args.map(|a| a.into_iter().map(|(s, _)| s).collect::<Vec<_>>());
+  write_vars(|v| v.descend(argv));
+  guard((), |_| {
+    write_vars(|v| v.ascend());
+  })
+}
+
+pub fn shared_scope_guard() -> impl Drop {
+  write_vars(|v| v.descend(None));
+  guard((), |_| {
+    write_vars(|v| v.ascend());
+  })
+}
+
+// ============================================================================
+// VarCtxGuard — RAII variable context cleanup
+// ============================================================================
+
+pub fn var_ctx_guard(
+  vars: HashSet<String>,
+) -> scopeguard::ScopeGuard<HashSet<String>, impl FnOnce(HashSet<String>)> {
+  guard(vars, |vars| {
+    write_vars(|v| {
+      for var in &vars {
+        v.unset_var(var).ok();
+      }
+    });
+  })
+}
+
+// ============================================================================
+// RedirGuard — RAII I/O redirection restoration
+// ============================================================================
+
+#[derive(Debug)]
+pub struct RedirGuard(pub(crate) IoFrame);
+
+impl RedirGuard {
+  pub(crate) fn new(frame: IoFrame) -> Self {
+    Self(frame)
+  }
+  pub fn persist(mut self) {
+    use nix::unistd::close;
+    if let Some(saved) = self.0.saved_io.take() {
+      close(saved.0).ok();
+      close(saved.1).ok();
+      close(saved.2).ok();
+    }
+  }
+}
+
+impl Drop for RedirGuard {
+  fn drop(&mut self) {
+    self.0.restore().ok();
+  }
+}
+
+// ============================================================================
+// RawModeGuard — RAII terminal raw mode management
+// ============================================================================
+
+pub fn raw_mode() -> RawModeGuard {
+  let orig = termios::tcgetattr(unsafe { BorrowedFd::borrow_raw(*TTY_FILENO) })
+    .expect("Failed to get terminal attributes");
+  let mut raw = orig.clone();
+  termios::cfmakeraw(&mut raw);
+  // Keep ISIG enabled so Ctrl+C/Ctrl+Z still generate signals
+  raw.local_flags |= termios::LocalFlags::ISIG;
+  // Keep OPOST enabled so \n is translated to \r\n on output
+  raw.output_flags |= termios::OutputFlags::OPOST;
+  termios::tcsetattr(
+    unsafe { BorrowedFd::borrow_raw(*TTY_FILENO) },
+    termios::SetArg::TCSANOW,
+    &raw,
+  )
+  .expect("Failed to set terminal to raw mode");
+
+  let (_cols, _rows) = get_win_size(*TTY_FILENO);
+
+  ORIG_TERMIOS.with(|cell| *cell.borrow_mut() = Some(orig.clone()));
+
+  RawModeGuard {
+    orig,
+    fd: *TTY_FILENO,
+  }
+}
+
+pub struct RawModeGuard {
+  orig: termios::Termios,
+  fd: RawFd,
+}
+
+impl RawModeGuard {
+  /// Disable raw mode temporarily for a specific operation
+  pub fn disable_for<F: FnOnce() -> R, R>(&self, func: F) -> R {
+    unsafe {
+      let fd = BorrowedFd::borrow_raw(self.fd);
+      // Temporarily restore the original termios
+      termios::tcsetattr(fd, termios::SetArg::TCSANOW, &self.orig)
+        .expect("Failed to temporarily disable raw mode");
+
+      // Run the function
+      let result = func();
+
+      // Re-enable raw mode
+      let mut raw = self.orig.clone();
+      termios::cfmakeraw(&mut raw);
+      // Keep ISIG enabled so Ctrl+C/Ctrl+Z still generate signals
+      raw.local_flags |= termios::LocalFlags::ISIG;
+      // Keep OPOST enabled so \n is translated to \r\n on output
+      raw.output_flags |= termios::OutputFlags::OPOST;
+      termios::tcsetattr(fd, termios::SetArg::TCSANOW, &raw).expect("Failed to re-enable raw mode");
+
+      result
+    }
+  }
+
+  pub fn with_cooked_mode<F, R>(f: F) -> R
+  where
+    F: FnOnce() -> R,
+  {
+    let current = tcgetattr(borrow_fd(*TTY_FILENO)).expect("Failed to get terminal attributes");
+    let orig = ORIG_TERMIOS.with(|cell| cell.borrow().clone())
+      .expect("with_cooked_mode called before raw_mode()");
+    tcsetattr(borrow_fd(*TTY_FILENO), termios::SetArg::TCSANOW, &orig)
+      .expect("Failed to restore cooked mode");
+    let res = f();
+    tcsetattr(borrow_fd(*TTY_FILENO), termios::SetArg::TCSANOW, &current)
+      .expect("Failed to restore raw mode");
+    res
+  }
+}
+
+impl Drop for RawModeGuard {
+  fn drop(&mut self) {
+    unsafe {
+      let _ = termios::tcsetattr(
+        BorrowedFd::borrow_raw(self.fd),
+        termios::SetArg::TCSANOW,
+        &self.orig,
+      );
+    }
+  }
+}
+
+// ============================================================================
+// TermiosGuard — RAII termios state management
+// ============================================================================
+
+#[derive(Debug)]
+pub struct TermiosGuard {
+  saved_termios: Option<Termios>,
+}
+
+impl TermiosGuard {
+  pub fn new(new_termios: Termios) -> Self {
+    let mut new = Self {
+      saved_termios: None,
+    };
+
+    if isatty(*TTY_FILENO).unwrap() {
+      let current_termios = termios::tcgetattr(std::io::stdin()).unwrap();
+      new.saved_termios = Some(current_termios);
+
+      termios::tcsetattr(
+        std::io::stdin(),
+        nix::sys::termios::SetArg::TCSANOW,
+        &new_termios,
+      )
+      .unwrap();
+    }
+
+    new
+  }
+}
+
+impl Default for TermiosGuard {
+  fn default() -> Self {
+    let mut termios_val = termios::tcgetattr(std::io::stdin()).unwrap();
+    termios_val.local_flags &= !LocalFlags::ECHOCTL;
+    Self::new(termios_val)
+  }
+}
+
+impl Drop for TermiosGuard {
+  fn drop(&mut self) {
+    if let Some(saved) = &self.saved_termios {
+      termios::tcsetattr(std::io::stdin(), nix::sys::termios::SetArg::TCSANOW, saved).unwrap();
+    }
+  }
+}