implement tilde expansion for ~user and ~uid using nix User lookups

implemented backtick command subs

deferred heredoc expansion until redir time instead of parse time

implemented "$*" expansions

function defs like 'func   ()  { }' now parse correctly

fixed conjunctions short circuiting instead of skipping

README.md

@@ -8,7 +8,7 @@ A Linux shell written in Rust. The name is a nod to the original Unix utilities
 
 ### Line Editor
 
-`shed` includes a built-in `vim` emulator as its line editor, written from scratch. It aims to provide a more precise vim-like editing experience at the shell prompt.
+`shed` includes a built-in `vim` emulator as its line editor, written from scratch. It aims to provide a more precise vim-like editing experience at the shell prompt than conventional `vi` mode implementations.
 
 - **Normal mode** - motions (`w`, `b`, `e`, `f`, `t`, `%`, `0`, `$`, etc.), verbs (`d`, `c`, `y`, `p`, `r`, `x`, `~`, etc.), text objects (`iw`, `aw`, `i"`, `a{`, `is`, etc.), registers, `.` repeat, `;`/`,` repeat, and counts
 - **Insert mode** - insert, append, replace, with Ctrl+W word deletion and undo/redo

src/builtin/mod.rs

@@ -18,6 +18,7 @@ pub mod map;
 pub mod pwd;
 pub mod read;
 pub mod resource;
+pub mod seek;
 pub mod shift;
 pub mod shopt;
 pub mod source;
@@ -25,12 +26,12 @@ pub mod test; // [[ ]] thing
 pub mod trap;
 pub mod varcmds;
 
-pub const BUILTINS: [&str; 49] = [
+pub const BUILTINS: [&str; 50] = [
   "echo", "cd", "read", "export", "local", "pwd", "source", ".", "shift", "jobs", "fg", "bg",
   "disown", "alias", "unalias", "return", "break", "continue", "exit", "shopt", "builtin",
   "command", "trap", "pushd", "popd", "dirs", "exec", "eval", "true", "false", ":", "readonly",
   "unset", "complete", "compgen", "map", "pop", "fpop", "push", "fpush", "rotate", "wait", "type",
-  "getopts", "keymap", "read_key", "autocmd", "ulimit", "umask",
+  "getopts", "keymap", "read_key", "autocmd", "ulimit", "umask", "seek",
 ];
 
 pub fn true_builtin() -> ShResult<()> {

src/builtin/seek.rs

@@ -0,0 +1,263 @@
+use nix::{
+  libc::STDOUT_FILENO,
+  unistd::{Whence, lseek, write},
+};
+
+use crate::{
+  getopt::{Opt, OptSpec, get_opts_from_tokens},
+  libsh::error::{ShErr, ShErrKind, ShResult},
+  parse::{NdRule, Node, execute::prepare_argv},
+  procio::borrow_fd,
+  state,
+};
+
+pub const LSEEK_OPTS: [OptSpec; 2] = [
+  OptSpec {
+    opt: Opt::Short('c'),
+    takes_arg: false,
+  },
+  OptSpec {
+    opt: Opt::Short('e'),
+    takes_arg: false,
+  },
+];
+
+pub struct LseekOpts {
+  cursor_rel: bool,
+  end_rel: bool,
+}
+
+pub fn seek(node: Node) -> ShResult<()> {
+  let NdRule::Command {
+    assignments: _,
+    argv,
+  } = node.class
+  else {
+    unreachable!()
+  };
+
+  let (argv, opts) = get_opts_from_tokens(argv, &LSEEK_OPTS)?;
+  let lseek_opts = get_lseek_opts(opts)?;
+  let mut argv = prepare_argv(argv)?.into_iter();
+  argv.next(); // drop 'seek'
+
+  let Some(fd) = argv.next() else {
+    return Err(ShErr::simple(
+      ShErrKind::ExecFail,
+      "lseek: Missing required argument 'fd'",
+    ));
+  };
+  let Ok(fd) = fd.0.parse::<u32>() else {
+    return Err(
+      ShErr::at(ShErrKind::ExecFail, fd.1, "Invalid file descriptor")
+        .with_note("file descriptors are integers"),
+    );
+  };
+
+  let Some(offset) = argv.next() else {
+    return Err(ShErr::simple(
+      ShErrKind::ExecFail,
+      "lseek: Missing required argument 'offset'",
+    ));
+  };
+  let Ok(offset) = offset.0.parse::<i64>() else {
+    return Err(
+      ShErr::at(ShErrKind::ExecFail, offset.1, "Invalid offset")
+        .with_note("offset can be a positive or negative integer"),
+    );
+  };
+
+  let whence = if lseek_opts.cursor_rel {
+    Whence::SeekCur
+  } else if lseek_opts.end_rel {
+    Whence::SeekEnd
+  } else {
+    Whence::SeekSet
+  };
+
+  match lseek(fd as i32, offset, whence) {
+    Ok(new_offset) => {
+      let stdout = borrow_fd(STDOUT_FILENO);
+      let buf = new_offset.to_string() + "\n";
+      write(stdout, buf.as_bytes())?;
+    }
+    Err(e) => {
+      state::set_status(1);
+      return Err(e.into());
+    }
+  }
+
+  state::set_status(0);
+  Ok(())
+}
+
+pub fn get_lseek_opts(opts: Vec<Opt>) -> ShResult<LseekOpts> {
+  let mut lseek_opts = LseekOpts {
+    cursor_rel: false,
+    end_rel: false,
+  };
+
+  for opt in opts {
+    match opt {
+      Opt::Short('c') => lseek_opts.cursor_rel = true,
+      Opt::Short('e') => lseek_opts.end_rel = true,
+      _ => {
+        return Err(ShErr::simple(
+          ShErrKind::ExecFail,
+          format!("lseek: Unexpected flag '{opt}'"),
+        ));
+      }
+    }
+  }
+
+  Ok(lseek_opts)
+}
+
+#[cfg(test)]
+mod tests {
+  use crate::testutil::{TestGuard, test_input};
+  use pretty_assertions::assert_eq;
+
+  #[test]
+  fn seek_set_beginning() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "hello world\n").unwrap();
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek 9 0").unwrap();
+
+    let out = g.read_output();
+    assert_eq!(out, "0\n");
+  }
+
+  #[test]
+  fn seek_set_offset() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "hello world\n").unwrap();
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek 9 6").unwrap();
+
+    let out = g.read_output();
+    assert_eq!(out, "6\n");
+  }
+
+  #[test]
+  fn seek_then_read() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "hello world\n").unwrap();
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek 9 6").unwrap();
+    // Clear the seek output
+    g.read_output();
+
+    test_input("read line <&9").unwrap();
+    let val = crate::state::read_vars(|v| v.get_var("line"));
+    assert_eq!(val, "world");
+  }
+
+  #[test]
+  fn seek_cur_relative() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "abcdefghij\n").unwrap();
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek 9 3").unwrap();
+    test_input("seek -c 9 4").unwrap();
+
+    let out = g.read_output();
+    assert_eq!(out, "3\n7\n");
+  }
+
+  #[test]
+  fn seek_end() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "hello\n").unwrap(); // 6 bytes
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek -e 9 0").unwrap();
+
+    let out = g.read_output();
+    assert_eq!(out, "6\n");
+  }
+
+  #[test]
+  fn seek_end_negative() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "hello\n").unwrap(); // 6 bytes
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek -e 9 -2").unwrap();
+
+    let out = g.read_output();
+    assert_eq!(out, "4\n");
+  }
+
+  #[test]
+  fn seek_write_overwrite() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "hello world\n").unwrap();
+    let _g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    test_input("seek 9 6").unwrap();
+    test_input("echo -n 'WORLD' >&9").unwrap();
+
+    let contents = std::fs::read_to_string(&path).unwrap();
+    assert_eq!(contents, "hello WORLD\n");
+  }
+
+  #[test]
+  fn seek_rewind_full_read() {
+    let dir = tempfile::TempDir::new().unwrap();
+    let path = dir.path().join("seek.txt");
+    std::fs::write(&path, "abc\n").unwrap();
+    let g = TestGuard::new();
+
+    test_input(format!("exec 9<> {}", path.display())).unwrap();
+    // Read moves cursor to EOF
+    test_input("read line <&9").unwrap();
+    // Rewind
+    test_input("seek 9 0").unwrap();
+    // Clear output from seek
+    g.read_output();
+    // Read again from beginning
+    test_input("read line <&9").unwrap();
+
+    let val = crate::state::read_vars(|v| v.get_var("line"));
+    assert_eq!(val, "abc");
+  }
+
+  #[test]
+  fn seek_bad_fd() {
+    let _g = TestGuard::new();
+
+    let result = test_input("seek 99 0");
+    assert!(result.is_err());
+  }
+
+  #[test]
+  fn seek_missing_args() {
+    let _g = TestGuard::new();
+
+    let result = test_input("seek");
+    assert!(result.is_err());
+
+    let result = test_input("seek 9");
+    assert!(result.is_err());
+  }
+}

src/expand.rs

@@ -4,6 +4,7 @@ use std::str::{Chars, FromStr};
 
 use ariadne::Fmt;
 use glob::Pattern;
+use nix::unistd::{Uid, User};
 use regex::Regex;
 
 use crate::libsh::error::{ShErr, ShErrKind, ShResult, ShResultExt, next_color};
@@ -40,18 +41,26 @@ impl Tk {
 }
 
 pub struct Expander {
+  flags: TkFlags,
   raw: String,
 }
 
 impl Expander {
   pub fn new(raw: Tk) -> ShResult<Self> {
-    let raw = raw.span.as_str();
-    Self::from_raw(raw)
+    let tk_raw = raw.span.as_str();
+    Self::from_raw(tk_raw, raw.flags)
   }
-  pub fn from_raw(raw: &str) -> ShResult<Self> {
+  pub fn from_raw(raw: &str, flags: TkFlags) -> ShResult<Self> {
     let raw = expand_braces_full(raw)?.join(" ");
-    let unescaped = unescape_str(&raw);
-    Ok(Self { raw: unescaped })
+    let unescaped = if flags.contains(TkFlags::IS_HEREDOC) {
+      unescape_heredoc(&raw)
+    } else {
+      unescape_str(&raw)
+    };
+    Ok(Self {
+      raw: unescaped,
+      flags,
+    })
   }
   pub fn expand(&mut self) -> ShResult<Vec<String>> {
     let mut chars = self.raw.chars().peekable();
@@ -75,8 +84,12 @@ impl Expander {
       self.raw.insert_str(0, "./");
     }
 
+    if self.flags.contains(TkFlags::IS_HEREDOC) {
+      Ok(vec![self.raw.clone()])
+    } else {
       Ok(self.split_words())
     }
+  }
   pub fn split_words(&mut self) -> Vec<String> {
     let mut words = vec![];
     let mut chars = self.raw.chars();
@@ -461,7 +474,26 @@ pub fn expand_raw(chars: &mut Peekable<Chars<'_>>) -> ShResult<String> {
   while let Some(ch) = chars.next() {
     match ch {
       markers::TILDE_SUB => {
-        let home = env::var("HOME").unwrap_or_default();
+				let mut username = String::new();
+				while chars.peek().is_some_and(|ch| *ch != '/') {
+					let ch = chars.next().unwrap();
+					username.push(ch);
+				}
+				let home = if username.is_empty() {
+					env::var("HOME").unwrap_or_default()
+				}
+				else if let Ok(result) = User::from_name(&username)
+				&& let Some(user) = result {
+					user.dir.to_string_lossy().to_string()
+				}
+				else if let Ok(id) = username.parse::<u32>()
+				&& let Ok(result) = User::from_uid(Uid::from_raw(id))
+				&& let Some(user) = result {
+					user.dir.to_string_lossy().to_string()
+				}
+				else {
+					format!("~{username}")
+				};
         result.push_str(&home);
       }
       markers::PROC_SUB_OUT => {
@@ -1154,6 +1186,25 @@ pub fn unescape_str(raw: &str) -> String {
                 }
               }
             }
+            '`' => {
+              result.push(markers::VAR_SUB);
+              result.push(markers::SUBSH);
+              while let Some(bt_ch) = chars.next() {
+                match bt_ch {
+                  '\\' => {
+                    result.push(bt_ch);
+                    if let Some(next_ch) = chars.next() {
+                      result.push(next_ch);
+                    }
+                  }
+                  '`' => {
+                    result.push(markers::SUBSH);
+                    break;
+                  }
+                  _ => result.push(bt_ch),
+                }
+              }
+            }
             '"' => {
               result.push(markers::DUB_QUOTE);
               break;
@@ -1318,6 +1369,25 @@ pub fn unescape_str(raw: &str) -> String {
           result.push('$');
         }
       }
+      '`' => {
+        result.push(markers::VAR_SUB);
+        result.push(markers::SUBSH);
+        while let Some(bt_ch) = chars.next() {
+          match bt_ch {
+            '\\' => {
+              result.push(bt_ch);
+              if let Some(next_ch) = chars.next() {
+                result.push(next_ch);
+              }
+            }
+            '`' => {
+              result.push(markers::SUBSH);
+              break;
+            }
+            _ => result.push(bt_ch),
+          }
+        }
+      }
       _ => result.push(ch),
     }
     first_char = false;
@@ -1326,6 +1396,96 @@ pub fn unescape_str(raw: &str) -> String {
   result
 }
 
+/// Like unescape_str but for heredoc bodies. Only processes:
+/// - $var / ${var} / $(cmd) substitution markers
+/// - Backslash escapes (only before $, `, \, and newline)
+/// Everything else (quotes, tildes, globs, process subs, etc.) is literal.
+pub fn unescape_heredoc(raw: &str) -> String {
+  let mut chars = raw.chars().peekable();
+  let mut result = String::new();
+
+  while let Some(ch) = chars.next() {
+    match ch {
+      '\\' => {
+        match chars.peek() {
+          Some('$') | Some('`') | Some('\\') | Some('\n') => {
+            let next_ch = chars.next().unwrap();
+            if next_ch == '\n' {
+              // line continuation — discard both backslash and newline
+              continue;
+            }
+            result.push(markers::ESCAPE);
+            result.push(next_ch);
+          }
+          _ => {
+            // backslash is literal
+            result.push('\\');
+          }
+        }
+      }
+      '$' if chars.peek() == Some(&'(') => {
+        result.push(markers::VAR_SUB);
+        chars.next(); // consume '('
+        result.push(markers::SUBSH);
+        let mut paren_count = 1;
+        while let Some(subsh_ch) = chars.next() {
+          match subsh_ch {
+            '\\' => {
+              result.push(subsh_ch);
+              if let Some(next_ch) = chars.next() {
+                result.push(next_ch);
+              }
+            }
+            '(' => {
+              paren_count += 1;
+              result.push(subsh_ch);
+            }
+            ')' => {
+              paren_count -= 1;
+              if paren_count == 0 {
+                result.push(markers::SUBSH);
+                break;
+              } else {
+                result.push(subsh_ch);
+              }
+            }
+            _ => result.push(subsh_ch),
+          }
+        }
+      }
+      '$' => {
+        result.push(markers::VAR_SUB);
+        if chars.peek() == Some(&'$') {
+          chars.next();
+          result.push('$');
+        }
+      }
+      '`' => {
+        result.push(markers::VAR_SUB);
+        result.push(markers::SUBSH);
+        while let Some(bt_ch) = chars.next() {
+          match bt_ch {
+            '\\' => {
+              result.push(bt_ch);
+              if let Some(next_ch) = chars.next() {
+                result.push(next_ch);
+              }
+            }
+            '`' => {
+              result.push(markers::SUBSH);
+              break;
+            }
+            _ => result.push(bt_ch),
+          }
+        }
+      }
+      _ => result.push(ch),
+    }
+  }
+
+  result
+}
+
 /// Opposite of unescape_str - escapes a string to be executed as literal text
 /// Used for completion results, and glob filename matches.
 pub fn escape_str(raw: &str, use_marker: bool) -> String {
@@ -3532,6 +3692,7 @@ mod tests {
 
     let mut exp = Expander {
       raw: "hello world\tfoo".to_string(),
+      flags: TkFlags::empty(),
     };
     let words = exp.split_words();
     assert_eq!(words, vec!["hello", "world", "foo"]);
@@ -3546,6 +3707,7 @@ mod tests {
 
     let mut exp = Expander {
       raw: "a:b:c".to_string(),
+      flags: TkFlags::empty(),
     };
     let words = exp.split_words();
     assert_eq!(words, vec!["a", "b", "c"]);
@@ -3560,6 +3722,7 @@ mod tests {
 
     let mut exp = Expander {
       raw: "hello world".to_string(),
+      flags: TkFlags::empty(),
     };
     let words = exp.split_words();
     assert_eq!(words, vec!["hello world"]);
@@ -3570,7 +3733,10 @@ mod tests {
     let _guard = TestGuard::new();
 
     let raw = format!("{}hello world{}", markers::DUB_QUOTE, markers::DUB_QUOTE);
-    let mut exp = Expander { raw };
+    let mut exp = Expander {
+      raw,
+      flags: TkFlags::empty(),
+    };
     let words = exp.split_words();
     assert_eq!(words, vec!["hello world"]);
   }
@@ -3582,7 +3748,10 @@ mod tests {
     let _guard = TestGuard::new();
 
     let raw = format!("hello{}world", unescape_str("\\ "));
-    let mut exp = Expander { raw };
+    let mut exp = Expander {
+      raw,
+      flags: TkFlags::empty(),
+    };
     let words = exp.split_words();
     assert_eq!(words, vec!["hello world"]);
   }
@@ -3592,7 +3761,10 @@ mod tests {
     let _guard = TestGuard::new();
 
     let raw = format!("hello{}world", unescape_str("\\\t"));
-    let mut exp = Expander { raw };
+    let mut exp = Expander {
+      raw,
+      flags: TkFlags::empty(),
+    };
     let words = exp.split_words();
     assert_eq!(words, vec!["hello\tworld"]);
   }
@@ -3605,7 +3777,10 @@ mod tests {
     }
 
     let raw = format!("a{}b:c", unescape_str("\\:"));
-    let mut exp = Expander { raw };
+    let mut exp = Expander {
+      raw,
+      flags: TkFlags::empty(),
+    };
     let words = exp.split_words();
     assert_eq!(words, vec!["a:b", "c"]);
   }

src/getopt.rs

@@ -95,12 +95,14 @@ pub fn sort_tks(
     .into_iter()
     .map(|t| t.expand())
     .collect::<ShResult<Vec<_>>>()?
-    .into_iter();
+    .into_iter()
+    .peekable();
   let mut opts = vec![];
   let mut non_opts = vec![];
 
   while let Some(token) = tokens_iter.next() {
     if &token.to_string() == "--" {
+      non_opts.push(token);
       non_opts.extend(tokens_iter);
       break;
     }

src/libsh/error.rs

@@ -201,6 +201,7 @@ impl ShErr {
   pub fn is_flow_control(&self) -> bool {
     self.kind.is_flow_control()
   }
+  /// Promotes a shell error from a simple error to an error that blames a span
   pub fn promote(mut self, span: Span) -> Self {
     if self.notes.is_empty() {
       return self;
@@ -208,6 +209,8 @@ impl ShErr {
     let first = self.notes[0].clone();
     if self.notes.len() > 1 {
       self.notes = self.notes[1..].to_vec();
+    } else {
+      self.notes = vec![];
     }
 
     self.labeled(span, first)

src/libsh/guards.rs

@@ -3,7 +3,7 @@ use std::collections::HashSet;
 use std::os::fd::{BorrowedFd, RawFd};
 
 use nix::sys::termios::{self, LocalFlags, Termios, tcgetattr, tcsetattr};
-use nix::unistd::isatty;
+use nix::unistd::{isatty, write};
 use scopeguard::guard;
 
 thread_local! {
@@ -147,11 +147,10 @@ impl RawModeGuard {
     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");
+    tcsetattr(borrow_fd(*TTY_FILENO), termios::SetArg::TCSANOW, &orig).ok();
     let res = f();
-    tcsetattr(borrow_fd(*TTY_FILENO), termios::SetArg::TCSANOW, &current)
-      .expect("Failed to restore raw mode");
+    tcsetattr(borrow_fd(*TTY_FILENO), termios::SetArg::TCSANOW, &current).ok();
+    unsafe { write(BorrowedFd::borrow_raw(*TTY_FILENO), b"\x1b[?1l\x1b>").ok() };
     res
   }
 }
@@ -159,11 +158,12 @@ impl RawModeGuard {
 impl Drop for RawModeGuard {
   fn drop(&mut self) {
     unsafe {
-      let _ = termios::tcsetattr(
+      termios::tcsetattr(
         BorrowedFd::borrow_raw(self.fd),
         termios::SetArg::TCSANOW,
         &self.orig,
-      );
+      )
+      .ok();
     }
   }
 }

src/libsh/sys.rs

@@ -2,6 +2,15 @@ use std::sync::LazyLock;
 
 use crate::prelude::*;
 
+/// Minimum fd number for shell-internal file descriptors.
+const MIN_INTERNAL_FD: RawFd = 10;
+
 pub static TTY_FILENO: LazyLock<RawFd> = LazyLock::new(|| {
-  open("/dev/tty", OFlag::O_RDWR, Mode::empty()).expect("Failed to open /dev/tty")
+  let fd = open("/dev/tty", OFlag::O_RDWR, Mode::empty()).expect("Failed to open /dev/tty");
+  // Move the tty fd above the user-accessible range so that
+  // `exec 3>&-` and friends don't collide with shell internals.
+  let high =
+    fcntl(fd, FcntlArg::F_DUPFD_CLOEXEC(MIN_INTERNAL_FD)).expect("Failed to dup /dev/tty high");
+  close(fd).ok();
+  high
 });

src/main.rs

@@ -31,7 +31,6 @@ use nix::unistd::read;
 use crate::builtin::keymap::KeyMapMatch;
 use crate::builtin::trap::TrapTarget;
 use crate::libsh::error::{self, ShErr, ShErrKind, ShResult};
-use crate::libsh::guards::scope_guard;
 use crate::libsh::sys::TTY_FILENO;
 use crate::libsh::utils::AutoCmdVecUtils;
 use crate::parse::execute::{exec_dash_c, exec_input};

src/parse/execute.rs

@@ -24,6 +24,7 @@ use crate::{
     pwd::pwd,
     read::{self, read_builtin},
     resource::{ulimit, umask_builtin},
+    seek::seek,
     shift::shift,
     shopt::shopt,
     source::source,
@@ -340,24 +341,19 @@ impl Dispatcher {
     };
 
     let mut elem_iter = elements.into_iter();
+    let mut skip = false;
     while let Some(element) = elem_iter.next() {
       let ConjunctNode { cmd, operator } = element;
+      if !skip {
         self.dispatch_node(*cmd)?;
+      }
 
       let status = state::get_status();
-      match operator {
-        ConjunctOp::And => {
-          if status != 0 {
-            break;
-          }
-        }
-        ConjunctOp::Or => {
-          if status == 0 {
-            break;
-          }
-        }
+      skip = match operator {
+        ConjunctOp::And => status != 0,
+        ConjunctOp::Or => status == 0,
         ConjunctOp::Null => break,
-      }
+      };
     }
     Ok(())
   }
@@ -377,7 +373,11 @@ impl Dispatcher {
     };
     let body_span = body.get_span();
     let body = body_span.as_str().to_string();
-    let name = name.span.as_str().strip_suffix("()").unwrap();
+    let name = name
+      .span
+      .as_str()
+      .strip_suffix("()")
+      .unwrap_or(name.span.as_str());
 
     if KEYWORDS.contains(&name) {
       return Err(ShErr::at(
@@ -803,7 +803,7 @@ impl Dispatcher {
     self.job_stack.new_job();
     if cmds.len() == 1 {
       self.fg_job = !is_bg && self.interactive;
-      let mut cmd = cmds.into_iter().next().unwrap();
+      let cmd = cmds.into_iter().next().unwrap();
       if is_bg && !matches!(cmd.class, NdRule::Command { .. }) {
         self.run_fork(
           &cmd.get_command().map(|t| t.to_string()).unwrap_or_default(),
@@ -888,7 +888,10 @@ impl Dispatcher {
 
     if fork_builtins {
       log::trace!("Forking builtin: {}", cmd_raw);
-      let _guard = self.io_stack.pop_frame().redirect()?;
+      let guard = self.io_stack.pop_frame().redirect()?;
+      if cmd_raw.as_str() == "exec" {
+        guard.persist();
+      }
       self.run_fork(&cmd_raw, |s| {
         if let Err(e) = s.dispatch_builtin(cmd) {
           e.print_error();
@@ -1013,6 +1016,7 @@ impl Dispatcher {
       "autocmd" => autocmd(cmd),
       "ulimit" => ulimit(cmd),
       "umask" => umask_builtin(cmd),
+      "seek" => seek(cmd),
       "true" | ":" => {
         state::set_status(0);
         Ok(())

src/parse/lex.rs

@@ -217,6 +217,31 @@ impl Tk {
     };
     self.span.as_str().trim() == ";;"
   }
+
+  pub fn is_opener(&self) -> bool {
+    OPENERS.contains(&self.as_str())
+      || matches!(self.class, TkRule::BraceGrpStart)
+      || matches!(self.class, TkRule::CasePattern)
+  }
+  pub fn is_closer(&self) -> bool {
+    matches!(self.as_str(), "fi" | "done" | "esac")
+      || self.has_double_semi()
+      || matches!(self.class, TkRule::BraceGrpEnd)
+  }
+
+  pub fn is_closer_for(&self, other: &Tk) -> bool {
+    if (matches!(other.class, TkRule::BraceGrpStart) && matches!(self.class, TkRule::BraceGrpEnd))
+      || (matches!(other.class, TkRule::CasePattern) && self.has_double_semi())
+    {
+      return true;
+    }
+    match other.as_str() {
+      "for" | "while" | "until" => matches!(self.as_str(), "done"),
+      "if" => matches!(self.as_str(), "fi"),
+      "case" => matches!(self.as_str(), "esac"),
+      _ => false,
+    }
+  }
 }
 
 impl Display for Tk {
@@ -241,20 +266,12 @@ bitflags! {
     const ASSIGN       = 0b0000000001000000;
     const BUILTIN      = 0b0000000010000000;
     const IS_PROCSUB   = 0b0000000100000000;
+    const IS_HEREDOC   = 0b0000001000000000;
+    const LIT_HEREDOC  = 0b0000010000000000;
+    const TAB_HEREDOC  = 0b0000100000000000;
   }
 }
 
-pub struct LexStream {
-  source: Arc<String>,
-  pub cursor: usize,
-  pub name: String,
-  quote_state: QuoteState,
-  brc_grp_depth: usize,
-  brc_grp_start: Option<usize>,
-  case_depth: usize,
-  flags: LexFlags,
-}
-
 bitflags! {
   #[derive(Debug, Clone, Copy)]
   pub struct LexFlags: u32 {
@@ -296,6 +313,18 @@ pub fn clean_input(input: &str) -> String {
   output
 }
 
+pub struct LexStream {
+  source: Arc<String>,
+  pub cursor: usize,
+  pub name: String,
+  quote_state: QuoteState,
+  brc_grp_depth: usize,
+  brc_grp_start: Option<usize>,
+  case_depth: usize,
+  heredoc_skip: Option<usize>,
+  flags: LexFlags,
+}
+
 impl LexStream {
   pub fn new(source: Arc<String>, flags: LexFlags) -> Self {
     let flags = flags | LexFlags::FRESH | LexFlags::NEXT_IS_CMD;
@@ -307,6 +336,7 @@ impl LexStream {
       quote_state: QuoteState::default(),
       brc_grp_depth: 0,
       brc_grp_start: None,
+      heredoc_skip: None,
       case_depth: 0,
     }
   }
@@ -367,7 +397,7 @@ impl LexStream {
   }
   pub fn read_redir(&mut self) -> Option<ShResult<Tk>> {
     assert!(self.cursor <= self.source.len());
-    let slice = self.slice(self.cursor..)?;
+    let slice = self.slice(self.cursor..)?.to_string();
     let mut pos = self.cursor;
     let mut chars = slice.chars().peekable();
     let mut tk = Tk::default();
@@ -379,20 +409,38 @@ impl LexStream {
             return None; // It's a process sub
           }
           pos += 1;
+          if let Some('|') = chars.peek() {
+            // noclobber force '>|'
+            chars.next();
+            pos += 1;
+            tk = self.get_token(self.cursor..pos, TkRule::Redir);
+            break;
+          }
+
           if let Some('>') = chars.peek() {
             chars.next();
             pos += 1;
           }
-          if let Some('&') = chars.peek() {
+          let Some('&') = chars.peek() else {
+            tk = self.get_token(self.cursor..pos, TkRule::Redir);
+            break;
+          };
+
           chars.next();
           pos += 1;
 
           let mut found_fd = false;
+          if chars.peek().is_some_and(|ch| *ch == '-') {
+            chars.next();
+            found_fd = true;
+            pos += 1;
+          } else {
             while chars.peek().is_some_and(|ch| ch.is_ascii_digit()) {
               chars.next();
               found_fd = true;
               pos += 1;
             }
+          }
 
           if !found_fd && !self.flags.contains(LexFlags::LEX_UNFINISHED) {
             let span_start = self.cursor;
@@ -406,10 +454,6 @@ impl LexStream {
             tk = self.get_token(self.cursor..pos, TkRule::Redir);
             break;
           }
-          } else {
-            tk = self.get_token(self.cursor..pos, TkRule::Redir);
-            break;
-          }
         }
         '<' => {
           if chars.peek() == Some(&'(') {
@@ -417,14 +461,94 @@ impl LexStream {
           }
           pos += 1;
 
-          for _ in 0..2 {
-            if let Some('<') = chars.peek() {
+          match chars.peek() {
+            Some('<') => {
               chars.next();
               pos += 1;
+
+              match chars.peek() {
+                Some('<') => {
+                  chars.next();
+                  pos += 1;
+                }
+
+                Some(ch) => {
+                  let mut ch = *ch;
+                  while is_field_sep(ch) {
+                    let Some(next_ch) = chars.next() else {
+                      // Incomplete input — fall through to emit << as Redir
+                      break;
+                    };
+                    pos += next_ch.len_utf8();
+                    ch = next_ch;
+                  }
+
+                  if is_field_sep(ch) {
+                    // Ran out of input while skipping whitespace — fall through
                   } else {
+                    let saved_cursor = self.cursor;
+                    match self.read_heredoc(pos) {
+                      Ok(Some(heredoc_tk)) => {
+                        // cursor is set to after the delimiter word;
+                        // heredoc_skip is set to after the body
+                        pos = self.cursor;
+                        self.cursor = saved_cursor;
+                        tk = heredoc_tk;
+                        break;
+                      }
+                      Ok(None) => {
+                        // Incomplete heredoc — restore cursor and fall through
+                        self.cursor = saved_cursor;
+                      }
+                      Err(e) => return Some(Err(e)),
+                    }
+                  }
+                }
+                _ => {
+                  // No delimiter yet — input is incomplete
+                  // Fall through to emit the << as a Redir token
+                }
+              }
+            }
+            Some('>') => {
+              chars.next();
+              pos += 1;
+              tk = self.get_token(self.cursor..pos, TkRule::Redir);
+              break;
+            }
+            Some('&') => {
+              chars.next();
+              pos += 1;
+
+              let mut found_fd = false;
+              if chars.peek().is_some_and(|ch| *ch == '-') {
+                chars.next();
+                found_fd = true;
+                pos += 1;
+              } else {
+                while chars.peek().is_some_and(|ch| ch.is_ascii_digit()) {
+                  chars.next();
+                  found_fd = true;
+                  pos += 1;
+                }
+              }
+
+              if !found_fd && !self.flags.contains(LexFlags::LEX_UNFINISHED) {
+                let span_start = self.cursor;
+                self.cursor = pos;
+                return Some(Err(ShErr::at(
+                  ShErrKind::ParseErr,
+                  Span::new(span_start..pos, self.source.clone()),
+                  "Invalid redirection",
+                )));
+              } else {
+                tk = self.get_token(self.cursor..pos, TkRule::Redir);
                 break;
               }
             }
+            _ => {}
+          }
+
           tk = self.get_token(self.cursor..pos, TkRule::Redir);
           break;
         }
@@ -448,6 +572,133 @@ impl LexStream {
     self.cursor = pos;
     Some(Ok(tk))
   }
+  pub fn read_heredoc(&mut self, mut pos: usize) -> ShResult<Option<Tk>> {
+    let slice = self.slice(pos..).unwrap_or_default().to_string();
+    let mut chars = slice.chars();
+    let mut delim = String::new();
+    let mut flags = TkFlags::empty();
+    let mut first_char = true;
+    // Parse the delimiter word, stripping quotes
+    while let Some(ch) = chars.next() {
+      match ch {
+        '-' if first_char => {
+          pos += 1;
+          flags |= TkFlags::TAB_HEREDOC;
+        }
+        '\"' => {
+          pos += 1;
+          self.quote_state.toggle_double();
+          flags |= TkFlags::LIT_HEREDOC;
+        }
+        '\'' => {
+          pos += 1;
+          self.quote_state.toggle_single();
+          flags |= TkFlags::LIT_HEREDOC;
+        }
+        _ if self.quote_state.in_quote() => {
+          pos += ch.len_utf8();
+          delim.push(ch);
+        }
+        ch if is_hard_sep(ch) => {
+          break;
+        }
+        ch => {
+          pos += ch.len_utf8();
+          delim.push(ch);
+        }
+      }
+      first_char = false;
+    }
+
+    // pos is now right after the delimiter word — this is where
+    // the cursor should return so the rest of the line gets lexed
+    let cursor_after_delim = pos;
+
+    // Re-slice from cursor_after_delim so iterator and pos are in sync
+    // (the old chars iterator consumed the hard_sep without advancing pos)
+    let rest = self
+      .slice(cursor_after_delim..)
+      .unwrap_or_default()
+      .to_string();
+    let mut chars = rest.chars();
+
+    // Scan forward to the newline (or use heredoc_skip from a previous heredoc)
+    let body_start = if let Some(skip) = self.heredoc_skip {
+      // A previous heredoc on this line already read its body;
+      // our body starts where that one ended
+      let skip_offset = skip - cursor_after_delim;
+      for _ in 0..skip_offset {
+        chars.next();
+      }
+      skip
+    } else {
+      // Skip the rest of the current line to find where the body begins
+      let mut scan = pos;
+      let mut found_newline = false;
+      while let Some(ch) = chars.next() {
+        scan += ch.len_utf8();
+        if ch == '\n' {
+          found_newline = true;
+          break;
+        }
+      }
+      if !found_newline {
+        if self.flags.contains(LexFlags::LEX_UNFINISHED) {
+          return Ok(None);
+        } else {
+          return Err(ShErr::at(
+            ShErrKind::ParseErr,
+            Span::new(pos..pos, self.source.clone()),
+            "Heredoc delimiter not found",
+          ));
+        }
+      }
+      scan
+    };
+
+    pos = body_start;
+    let start = pos;
+
+    // Read lines until we find one that matches the delimiter exactly
+    let mut line = String::new();
+    let mut line_start = pos;
+    while let Some(ch) = chars.next() {
+      pos += ch.len_utf8();
+      if ch == '\n' {
+        let trimmed = line.trim_end_matches('\r');
+        if trimmed == delim {
+          let mut tk = self.get_token(start..line_start, TkRule::Redir);
+          tk.flags |= TkFlags::IS_HEREDOC | flags;
+          self.heredoc_skip = Some(pos);
+          self.cursor = cursor_after_delim;
+          return Ok(Some(tk));
+        }
+        line.clear();
+        line_start = pos;
+      } else {
+        line.push(ch);
+      }
+    }
+    // Check the last line (no trailing newline)
+    let trimmed = line.trim_end_matches('\r');
+    if trimmed == delim {
+      let mut tk = self.get_token(start..line_start, TkRule::Redir);
+      tk.flags |= TkFlags::IS_HEREDOC | flags;
+      self.heredoc_skip = Some(pos);
+      self.cursor = cursor_after_delim;
+      return Ok(Some(tk));
+    }
+
+    if !self.flags.contains(LexFlags::LEX_UNFINISHED) {
+      Err(ShErr::at(
+        ShErrKind::ParseErr,
+        Span::new(start..pos, self.source.clone()),
+        format!("Heredoc delimiter '{}' not found", delim),
+      ))
+    } else {
+      Ok(None)
+    }
+  }
   pub fn read_string(&mut self) -> ShResult<Tk> {
     assert!(self.cursor <= self.source.len());
     let slice = self.slice_from_cursor().unwrap().to_string();
@@ -625,6 +876,16 @@ impl LexStream {
             ));
           }
         }
+        '(' if can_be_subshell && chars.peek() == Some(&')') => {
+          // standalone "()" — function definition marker
+          pos += 2;
+          chars.next();
+          let mut tk = self.get_token(self.cursor..pos, TkRule::Str);
+          tk.mark(TkFlags::KEYWORD);
+          self.cursor = pos;
+          self.set_next_is_cmd(true);
+          return Ok(tk);
+        }
         '(' if self.next_is_cmd() && can_be_subshell => {
           pos += 1;
           let mut paren_count = 1;
@@ -845,10 +1106,19 @@ impl Iterator for LexStream {
 
     let token = match get_char(&self.source, self.cursor).unwrap() {
       '\r' | '\n' | ';' => {
+        let ch = get_char(&self.source, self.cursor).unwrap();
         let ch_idx = self.cursor;
         self.cursor += 1;
         self.set_next_is_cmd(true);
 
+        // If a heredoc was parsed on this line, skip past the body
+        // Only on newline — ';' is a command separator within the same line
+        if (ch == '\n' || ch == '\r')
+          && let Some(skip) = self.heredoc_skip.take()
+        {
+          self.cursor = skip;
+        }
+
         while let Some(ch) = get_char(&self.source, self.cursor) {
           match ch {
             '\\' if get_char(&self.source, self.cursor + 1) == Some('\n') => {

src/prelude.rs

@@ -19,7 +19,7 @@ pub use std::os::unix::io::{AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd,
 pub use bitflags::bitflags;
 pub use nix::{
   errno::Errno,
-  fcntl::{OFlag, open},
+  fcntl::{FcntlArg, OFlag, fcntl, open},
   libc::{self, STDERR_FILENO, STDIN_FILENO, STDOUT_FILENO},
   sys::{
     signal::{self, SigHandler, SigSet, SigmaskHow, Signal, kill, killpg, pthread_sigmask, signal},

src/procio.rs

@@ -8,15 +8,27 @@ use crate::{
   expand::Expander,
   libsh::{
     error::{ShErr, ShErrKind, ShResult},
+    sys::TTY_FILENO,
     utils::RedirVecUtils,
   },
-  parse::{Redir, RedirType, get_redir_file},
+  parse::{Redir, RedirType, get_redir_file, lex::TkFlags},
   prelude::*,
+  state,
 };
 
 // Credit to fish-shell for many of the implementation ideas present in this
 // module https://fishshell.com/
 
+/// Minimum fd number for shell-internal file descriptors.
+/// User-visible fds (0-9) are kept clear so `exec 3>&-` etc. work as expected.
+const MIN_INTERNAL_FD: RawFd = 10;
+
+/// Like `dup()`, but places the new fd at `MIN_INTERNAL_FD` or above so it
+/// doesn't collide with user-managed fds.
+fn dup_high(fd: RawFd) -> nix::Result<RawFd> {
+  fcntl(fd, FcntlArg::F_DUPFD_CLOEXEC(MIN_INTERNAL_FD))
+}
+
 #[derive(Clone, Debug)]
 pub enum IoMode {
   Fd {
@@ -37,8 +49,9 @@ pub enum IoMode {
     pipe: Arc<OwnedFd>,
   },
   Buffer {
+    tgt_fd: RawFd,
     buf: String,
-    pipe: Arc<OwnedFd>,
+    flags: TkFlags, // so we can see if its a heredoc or not
   },
   Close {
     tgt_fd: RawFd,
@@ -79,19 +92,29 @@ impl IoMode {
     if let IoMode::File { tgt_fd, path, mode } = self {
       let path_raw = path.as_os_str().to_str().unwrap_or_default().to_string();
 
-      let expanded_path = Expander::from_raw(&path_raw)?.expand()?.join(" "); // should just be one string, will have to find some way to handle a return of
-      // multiple
+      let expanded_path = Expander::from_raw(&path_raw, TkFlags::empty())?
+        .expand()?
+        .join(" "); // should just be one string, will have to find some way to handle a return of multiple paths
 
       let expanded_pathbuf = PathBuf::from(expanded_path);
 
       let file = get_redir_file(mode, expanded_pathbuf)?;
+      // Move the opened fd above the user-accessible range so it never
+      // collides with the target fd (e.g. `3>/tmp/foo` where open() returns 3,
+      // causing dup2(3,3) to be a no-op and then OwnedFd drop closes it).
+      let raw = file.as_raw_fd();
+      let high = fcntl(raw, FcntlArg::F_DUPFD_CLOEXEC(MIN_INTERNAL_FD)).map_err(ShErr::from)?;
+      drop(file); // closes the original low fd
       self = IoMode::OpenedFile {
         tgt_fd,
-        file: Arc::new(OwnedFd::from(file)),
+        file: Arc::new(unsafe { OwnedFd::from_raw_fd(high) }),
       }
     }
     Ok(self)
   }
+  pub fn buffer(tgt_fd: RawFd, buf: String, flags: TkFlags) -> ShResult<Self> {
+    Ok(Self::Buffer { tgt_fd, buf, flags })
+  }
   pub fn get_pipes() -> (Self, Self) {
     let (rpipe, wpipe) = nix::unistd::pipe2(OFlag::O_CLOEXEC).unwrap();
     (
@@ -206,24 +229,107 @@ impl<'e> IoFrame {
     )
   }
   pub fn save(&'e mut self) {
-    let saved_in = dup(STDIN_FILENO).unwrap();
-    let saved_out = dup(STDOUT_FILENO).unwrap();
-    let saved_err = dup(STDERR_FILENO).unwrap();
+    let saved_in = dup_high(STDIN_FILENO).unwrap();
+    let saved_out = dup_high(STDOUT_FILENO).unwrap();
+    let saved_err = dup_high(STDERR_FILENO).unwrap();
     self.saved_io = Some(IoGroup(saved_in, saved_out, saved_err));
   }
   pub fn redirect(mut self) -> ShResult<RedirGuard> {
     self.save();
-    for redir in &mut self.redirs {
-      let io_mode = &mut redir.io_mode;
-      if let IoMode::File { .. } = io_mode {
-        *io_mode = io_mode.clone().open_file()?;
-      };
-      let tgt_fd = io_mode.tgt_fd();
-      let src_fd = io_mode.src_fd();
-      dup2(src_fd, tgt_fd)?;
+    if let Err(e) = self.apply_redirs() {
+      // Restore saved fds before propagating the error so they don't leak.
+      self.restore().ok();
+      return Err(e);
     }
     Ok(RedirGuard::new(self))
   }
+  fn apply_redirs(&mut self) -> ShResult<()> {
+    for redir in &mut self.redirs {
+      let io_mode = &mut redir.io_mode;
+      match io_mode {
+        IoMode::Close { tgt_fd } => {
+          if *tgt_fd == *TTY_FILENO {
+            // Don't let user close the shell's tty fd.
+            continue;
+          }
+          close(*tgt_fd).ok();
+          continue;
+        }
+        IoMode::File { .. } => match io_mode.clone().open_file() {
+          Ok(file) => *io_mode = file,
+          Err(e) => {
+            if let Some(span) = redir.span.as_ref() {
+              return Err(e.promote(span.clone()));
+            }
+            return Err(e);
+          }
+        },
+        IoMode::Buffer { tgt_fd, buf, flags } => {
+          let (rpipe, wpipe) = nix::unistd::pipe()?;
+          let mut text = if flags.contains(TkFlags::LIT_HEREDOC) {
+            buf.clone()
+          } else {
+            let words = Expander::from_raw(buf, *flags)?.expand()?;
+            if flags.contains(TkFlags::IS_HEREDOC) {
+              words.into_iter().next().unwrap_or_default()
+            } else {
+              let ifs = state::get_separator();
+              words.join(&ifs).trim().to_string() + "\n"
+            }
+          };
+          if flags.contains(TkFlags::TAB_HEREDOC) {
+            let lines = text.lines();
+            let mut min_tabs = usize::MAX;
+            for line in lines {
+              if line.is_empty() {
+                continue;
+              }
+              let line_len = line.len();
+              let after_strip = line.trim_start_matches('\t').len();
+              let delta = line_len - after_strip;
+              min_tabs = min_tabs.min(delta);
+            }
+            if min_tabs == usize::MAX {
+              // let's avoid possibly allocating a string with 18 quintillion tabs
+              min_tabs = 0;
+            }
+
+            if min_tabs > 0 {
+              let stripped = text
+                .lines()
+                .fold(vec![], |mut acc, ln| {
+                  if ln.is_empty() {
+                    acc.push("");
+                    return acc;
+                  }
+                  let stripped_ln = ln.strip_prefix(&"\t".repeat(min_tabs)).unwrap();
+                  acc.push(stripped_ln);
+                  acc
+                })
+                .join("\n");
+              text = stripped + "\n";
+            }
+          }
+          write(wpipe, text.as_bytes())?;
+          *io_mode = IoMode::Pipe {
+            tgt_fd: *tgt_fd,
+            pipe: rpipe.into(),
+          };
+        }
+        _ => {}
+      }
+      let tgt_fd = io_mode.tgt_fd();
+      let src_fd = io_mode.src_fd();
+      if let Err(e) = dup2(src_fd, tgt_fd) {
+        if let Some(span) = redir.span.as_ref() {
+          return Err(ShErr::from(e).promote(span.clone()));
+        } else {
+          return Err(e.into());
+        }
+      }
+    }
+    Ok(())
+  }
   pub fn restore(&mut self) -> ShResult<()> {
     if let Some(saved) = self.saved_io.take() {
       dup2(saved.0, STDIN_FILENO)?;
@@ -334,6 +440,8 @@ pub fn borrow_fd<'f>(fd: i32) -> BorrowedFd<'f> {
 }
 
 type PipeFrames = Map<PipeGenerator, fn((Option<Redir>, Option<Redir>)) -> IoFrame>;
+
+/// An iterator that lazily creates a specific number of pipes.
 pub struct PipeGenerator {
   num_cmds: usize,
   cursor: usize,

src/readline/complete.rs

@@ -1,7 +1,7 @@
 use std::{
   collections::HashSet,
   fmt::{Debug, Write},
-  path::{Path, PathBuf},
+  path::PathBuf,
   sync::Arc,
 };
 

src/readline/linebuf.rs

@@ -15,7 +15,7 @@ use crate::{
   libsh::{error::ShResult, guards::var_ctx_guard},
   parse::{
     execute::exec_input,
-    lex::{LexFlags, LexStream, QuoteState, Tk, TkFlags, TkRule},
+    lex::{LexFlags, LexStream, QuoteState, Tk, TkRule},
   },
   prelude::*,
   readline::{
@@ -350,6 +350,77 @@ impl ClampedUsize {
   }
 }
 
+#[derive(Default, Clone, Debug)]
+pub struct IndentCtx {
+  depth: usize,
+  ctx: Vec<Tk>,
+  in_escaped_line: bool,
+}
+
+impl IndentCtx {
+  pub fn new() -> Self {
+    Self::default()
+  }
+
+  pub fn depth(&self) -> usize {
+    self.depth
+  }
+
+  pub fn ctx(&self) -> &[Tk] {
+    &self.ctx
+  }
+
+  pub fn descend(&mut self, tk: Tk) {
+    self.ctx.push(tk);
+    self.depth += 1;
+  }
+
+  pub fn ascend(&mut self) {
+    self.depth = self.depth.saturating_sub(1);
+    self.ctx.pop();
+  }
+
+  pub fn reset(&mut self) {
+    std::mem::take(self);
+  }
+
+  pub fn check_tk(&mut self, tk: Tk) {
+    if tk.is_opener() {
+      self.descend(tk);
+    } else if self.ctx.last().is_some_and(|t| tk.is_closer_for(t)) {
+      self.ascend();
+    } else if matches!(tk.class, TkRule::Sep) && self.in_escaped_line {
+      self.in_escaped_line = false;
+      self.depth = self.depth.saturating_sub(1);
+    }
+  }
+
+  pub fn calculate(&mut self, input: &str) -> usize {
+    self.depth = 0;
+    self.ctx.clear();
+    self.in_escaped_line = false;
+
+    let input_arc = Arc::new(input.to_string());
+    let Ok(tokens) =
+      LexStream::new(input_arc, LexFlags::LEX_UNFINISHED).collect::<ShResult<Vec<Tk>>>()
+    else {
+      log::error!("Lexing failed during depth calculation: {:?}", input);
+      return 0;
+    };
+
+    for tk in tokens {
+      self.check_tk(tk);
+    }
+
+    if input.ends_with("\\\n") {
+      self.in_escaped_line = true;
+      self.depth += 1;
+    }
+
+    self.depth
+  }
+}
+
 #[derive(Default, Clone, Debug)]
 pub struct LineBuf {
   pub buffer: String,
@@ -363,7 +434,7 @@ pub struct LineBuf {
 
   pub insert_mode_start_pos: Option<usize>,
   pub saved_col: Option<usize>,
-  pub auto_indent_level: usize,
+  pub indent_ctx: IndentCtx,
 
   pub undo_stack: Vec<Edit>,
   pub redo_stack: Vec<Edit>,
@@ -617,6 +688,17 @@ impl LineBuf {
   pub fn read_slice_to_cursor(&self) -> Option<&str> {
     self.read_slice_to(self.cursor.get())
   }
+  pub fn cursor_is_escaped(&mut self) -> bool {
+    let Some(to_cursor) = self.slice_to_cursor() else {
+      return false;
+    };
+
+    // count the number of backslashes
+    let delta = to_cursor.len() - to_cursor.trim_end_matches('\\').len();
+
+    // an even number of backslashes means each one is escaped
+    delta % 2 != 0
+  }
   pub fn slice_to_cursor_inclusive(&mut self) -> Option<&str> {
     self.slice_to(self.cursor.ret_add(1))
   }
@@ -829,7 +911,7 @@ impl LineBuf {
     }
     Some(self.line_bounds(line_no))
   }
-  pub fn word_at(&mut self, pos: usize, word: Word) -> (usize, usize) {
+  pub fn word_at(&mut self, _pos: usize, word: Word) -> (usize, usize) {
     let start = if self.is_word_bound(self.cursor.get(), word, Direction::Backward) {
       self.cursor.get()
     } else {
@@ -2031,51 +2113,13 @@ impl LineBuf {
     let end = start + (new.len().max(gr.len()));
     self.buffer.replace_range(start..end, new);
   }
-  pub fn calc_indent_level(&mut self) {
-    // FIXME: This implementation is extremely naive but it kind of sort of works for now
-    // Need to re-implement it and write tests
+  pub fn calc_indent_level(&mut self) -> usize {
     let to_cursor = self
       .slice_to_cursor()
       .map(|s| s.to_string())
       .unwrap_or(self.buffer.clone());
 
-    let mut level: usize = 0;
-
-    if to_cursor.ends_with("\\\n") {
-      level += 1; // Line continuation, so we need to add an extra level
-    }
-
-    let input = Arc::new(to_cursor);
-    let Ok(tokens) = LexStream::new(input, LexFlags::LEX_UNFINISHED).collect::<ShResult<Vec<Tk>>>()
-    else {
-      log::error!("Failed to lex buffer for indent calculation");
-      return;
-    };
-    let mut last_keyword: Option<String> = None;
-    for tk in tokens {
-      if tk.flags.contains(TkFlags::KEYWORD) {
-        match tk.as_str() {
-          "in" => {
-            if last_keyword.as_deref() == Some("case") {
-              level += 1;
-            } else {
-              // 'in' is also used in for loops, but we already increment level on 'do' for those
-              // so we just skip it here
-            }
-          }
-          "then" | "do" => level += 1,
-          "done" | "fi" | "esac" => level = level.saturating_sub(1),
-          _ => { /* Continue */ }
-        }
-        last_keyword = Some(tk.to_string());
-      } else if tk.class == TkRule::BraceGrpStart {
-        level += 1;
-      } else if tk.class == TkRule::BraceGrpEnd {
-        level = level.saturating_sub(1);
-      }
-    }
-
-    self.auto_indent_level = level;
+    self.indent_ctx.calculate(&to_cursor)
   }
   pub fn eval_motion(&mut self, verb: Option<&Verb>, motion: MotionCmd) -> MotionKind {
     let buffer = self.buffer.clone();
@@ -2652,8 +2696,8 @@ impl LineBuf {
     register.write_to_register(register_content);
     self.cursor.set(start);
     if do_indent {
-      self.calc_indent_level();
-      let tabs = (0..self.auto_indent_level).map(|_| '\t');
+      let depth = self.calc_indent_level();
+      let tabs = (0..depth).map(|_| '\t');
       for tab in tabs {
         self.insert_at_cursor(tab);
         self.cursor.add(1);
@@ -2888,17 +2932,29 @@ impl LineBuf {
     };
     end = end.saturating_sub(1);
     let mut last_was_whitespace = false;
-    for i in start..end {
+    let mut last_was_escape = false;
+    let mut i = start;
+    while i < end {
       let Some(gr) = self.grapheme_at(i) else {
+        i += 1;
         continue;
       };
       if gr == "\n" {
         if last_was_whitespace {
           self.remove(i);
+          end -= 1;
         } else {
           self.force_replace_at(i, " ");
         }
+        if last_was_escape {
+          // if we are here, then we just joined an escaped newline
+          // semantically, echo foo\\nbar == echo foo bar
+          // so a joined line should remove the escape.
+          self.remove(i - 1);
+          end -= 1;
+        }
         last_was_whitespace = false;
+        last_was_escape = false;
         let strip_pos = if self.grapheme_at(i) == Some(" ") {
           i + 1
         } else {
@@ -2906,26 +2962,38 @@ impl LineBuf {
         };
         while self.grapheme_at(strip_pos) == Some("\t") {
           self.remove(strip_pos);
+          end -= 1;
         }
         self.cursor.set(i);
+        i += 1;
         continue;
+      } else if gr == "\\" {
+        if last_was_whitespace && last_was_escape {
+          // if we are here, then the pattern of the last three chars was this:
+          // ' \\', a space and two backslashes.
+          // This means the "last" was an escaped backslash, not whitespace.
+          last_was_whitespace = false;
         }
+        last_was_escape = !last_was_escape;
+      } else {
         last_was_whitespace = is_whitespace(gr);
+        last_was_escape = false;
+      }
+      i += 1;
     }
     Ok(())
   }
   fn verb_insert_char(&mut self, ch: char) {
     self.insert_at_cursor(ch);
     self.cursor.add(1);
-    let before = self.auto_indent_level;
-    if read_shopts(|o| o.prompt.auto_indent)
-      && let Some(line_content) = self.this_line_content()
-    {
-      match line_content.trim() {
-        "esac" | "done" | "fi" | "}" => {
-          self.calc_indent_level();
-          if self.auto_indent_level < before {
-            let delta = before - self.auto_indent_level;
+    let before_escaped = self.indent_ctx.in_escaped_line;
+    let before = self.indent_ctx.depth();
+    if read_shopts(|o| o.prompt.auto_indent) {
+      let after = self.calc_indent_level();
+      // Only dedent if the depth decrease came from a closer, not from
+      // a line continuation bonus going away
+      if after < before && !(before_escaped && !self.indent_ctx.in_escaped_line) {
+        let delta = before - after;
         let line_start = self.start_of_line();
         for _ in 0..delta {
           if self.grapheme_at(line_start).is_some_and(|gr| gr == "\t") {
@@ -2937,15 +3005,13 @@ impl LineBuf {
         }
       }
     }
-        _ => {}
-      }
-    }
   }
   fn verb_insert(&mut self, string: String) {
     self.insert_str_at_cursor(&string);
     let graphemes = string.graphemes(true).count();
     self.cursor.add(graphemes);
   }
+  #[allow(clippy::unnecessary_to_owned)]
   fn verb_indent(&mut self, motion: MotionKind) -> ShResult<()> {
     let Some((start, end)) = self.range_from_motion(&motion) else {
       return Ok(());
@@ -2975,6 +3041,7 @@ impl LineBuf {
     }
     Ok(())
   }
+  #[allow(clippy::unnecessary_to_owned)]
   fn verb_dedent(&mut self, motion: MotionKind) -> ShResult<()> {
     let Some((start, mut end)) = self.range_from_motion(&motion) else {
       return Ok(());
@@ -3017,8 +3084,8 @@ impl LineBuf {
         Anchor::After => {
           self.push('\n');
           if auto_indent {
-            self.calc_indent_level();
-            for _ in 0..self.auto_indent_level {
+            let depth = self.calc_indent_level();
+            for _ in 0..depth {
               self.push('\t');
             }
           }
@@ -3027,8 +3094,8 @@ impl LineBuf {
         }
         Anchor::Before => {
           if auto_indent {
-            self.calc_indent_level();
-            for _ in 0..self.auto_indent_level {
+            let depth = self.calc_indent_level();
+            for _ in 0..depth {
               self.insert_at(0, '\t');
             }
           }
@@ -3055,8 +3122,8 @@ impl LineBuf {
     self.insert_at_cursor('\n');
     self.cursor.add(1);
     if auto_indent {
-      self.calc_indent_level();
-      for _ in 0..self.auto_indent_level {
+      let depth = self.calc_indent_level();
+      for _ in 0..depth {
         self.insert_at_cursor('\t');
         self.cursor.add(1);
       }
@@ -3198,7 +3265,6 @@ impl LineBuf {
     }
     Ok(())
   }
-  #[allow(clippy::unnecessary_to_owned)]
   pub fn exec_verb(
     &mut self,
     verb: Verb,
@@ -3285,10 +3351,10 @@ impl LineBuf {
 
     /*
      * Let's evaluate the motion now
-     * If we got some weird command like 'dvw' we will have to simulate a visual
-     * selection to get the range If motion is None, we will try to use
-     * self.select_range If self.select_range is None, we will use
-     * MotionKind::Null
+     * If we got some weird command like 'dvw' we will
+     * have to simulate a visual selection to get the range
+     * If motion is None, we will try to use self.select_range
+     * If self.select_range is None, we will use MotionKind::Null
      */
     let motion_eval =
       if flags.intersects(CmdFlags::VISUAL | CmdFlags::VISUAL_LINE | CmdFlags::VISUAL_BLOCK) {

src/readline/mod.rs

@@ -253,7 +253,6 @@ pub struct ShedVi {
   pub repeat_action: Option<CmdReplay>,
   pub repeat_motion: Option<MotionCmd>,
   pub editor: LineBuf,
-  pub next_is_escaped: bool,
 
   pub old_layout: Option<Layout>,
   pub history: History,
@@ -271,7 +270,6 @@ impl ShedVi {
       completer: Box::new(FuzzyCompleter::default()),
       highlighter: Highlighter::new(),
       mode: Box::new(ViInsert::new()),
-      next_is_escaped: false,
       saved_mode: None,
       pending_keymap: Vec::new(),
       old_layout: None,
@@ -303,7 +301,6 @@ impl ShedVi {
       completer: Box::new(FuzzyCompleter::default()),
       highlighter: Highlighter::new(),
       mode: Box::new(ViInsert::new()),
-      next_is_escaped: false,
       saved_mode: None,
       pending_keymap: Vec::new(),
       old_layout: None,
@@ -417,7 +414,7 @@ impl ShedVi {
       LexStream::new(Arc::clone(&input), LexFlags::LEX_UNFINISHED).collect::<ShResult<Vec<_>>>();
     let lex_result2 =
       LexStream::new(Arc::clone(&input), LexFlags::empty()).collect::<ShResult<Vec<_>>>();
-    let is_top_level = self.editor.auto_indent_level == 0;
+    let is_top_level = self.editor.indent_ctx.ctx().is_empty();
 
     let is_complete = match (lex_result1.is_err(), lex_result2.is_err()) {
       (true, true) => {
@@ -444,11 +441,6 @@ impl ShedVi {
 
     // Process all available keys
     while let Some(key) = self.reader.read_key()? {
-      log::debug!(
-        "Read key: {key:?} in mode {:?}, self.reader.verbatim = {}",
-        self.mode.report_mode(),
-        self.reader.verbatim
-      );
       // If completer or history search are active, delegate input to it
       if self.history.fuzzy_finder.is_active() {
         self.print_line(false)?;
@@ -631,10 +623,6 @@ impl ShedVi {
 
   pub fn handle_key(&mut self, key: KeyEvent) -> ShResult<Option<ReadlineEvent>> {
     if self.should_accept_hint(&key) {
-      log::debug!(
-        "Accepting hint on key {key:?} in mode {:?}",
-        self.mode.report_mode()
-      );
       self.editor.accept_hint();
       if !self.history.at_pending() {
         self.history.reset_to_pending();
@@ -808,14 +796,6 @@ impl ShedVi {
       }
     }
 
-    if let KeyEvent(KeyCode::Char('\\'), ModKeys::NONE) = key
-      && !self.next_is_escaped
-    {
-      self.next_is_escaped = true;
-    } else {
-      self.next_is_escaped = false;
-    }
-
     let Ok(cmd) = self.mode.handle_key_fallible(key) else {
       // it's an ex mode error
       self.mode = Box::new(ViNormal::new()) as Box<dyn ViMode>;
@@ -834,8 +814,7 @@ impl ShedVi {
     }
 
     if cmd.is_submit_action()
-      && !self.next_is_escaped
-      && !self.editor.buffer.ends_with('\\')
+      && !self.editor.cursor_is_escaped()
       && (self.should_submit()? || !read_shopts(|o| o.prompt.linebreak_on_incomplete))
     {
       if self.editor.attempt_history_expansion(&self.history) {
@@ -1269,10 +1248,6 @@ impl ShedVi {
           for _ in 0..repeat {
             let cmds = cmds.clone();
             for (i, cmd) in cmds.iter().enumerate() {
-              log::debug!(
-                "Replaying command {cmd:?} in mode {:?}, replay {i}/{repeat}",
-                self.mode.report_mode()
-              );
               self.exec_cmd(cmd.clone(), true)?;
               // After the first command, start merging so all subsequent
               // edits fold into one undo entry (e.g. cw + inserted chars)
@@ -1623,6 +1598,12 @@ pub fn annotate_token(token: Tk) -> Vec<(usize, Marker)> {
 
   let mut insertions: Vec<(usize, Marker)> = vec![];
 
+  // Heredoc tokens have spans covering the body content far from the <<
+  // operator, which breaks position tracking after marker insertions
+  if token.flags.contains(TkFlags::IS_HEREDOC) {
+    return insertions;
+  }
+
   if token.class != TkRule::Str
     && let Some(marker) = marker_for(&token.class)
   {

src/readline/term.rs

@@ -294,12 +294,14 @@ impl Read for TermBuffer {
 
 struct KeyCollector {
   events: VecDeque<KeyEvent>,
+  ss3_pending: bool,
 }
 
 impl KeyCollector {
   fn new() -> Self {
     Self {
       events: VecDeque::new(),
+      ss3_pending: false,
     }
   }
 
@@ -337,7 +339,55 @@ impl Default for KeyCollector {
 
 impl Perform for KeyCollector {
   fn print(&mut self, c: char) {
+    log::trace!("print: {c:?}");
     // vte routes 0x7f (DEL) to print instead of execute
+    if self.ss3_pending {
+      self.ss3_pending = false;
+      match c {
+        'A' => {
+          self.push(KeyEvent(KeyCode::Up, ModKeys::empty()));
+          return;
+        }
+        'B' => {
+          self.push(KeyEvent(KeyCode::Down, ModKeys::empty()));
+          return;
+        }
+        'C' => {
+          self.push(KeyEvent(KeyCode::Right, ModKeys::empty()));
+          return;
+        }
+        'D' => {
+          self.push(KeyEvent(KeyCode::Left, ModKeys::empty()));
+          return;
+        }
+        'H' => {
+          self.push(KeyEvent(KeyCode::Home, ModKeys::empty()));
+          return;
+        }
+        'F' => {
+          self.push(KeyEvent(KeyCode::End, ModKeys::empty()));
+          return;
+        }
+        'P' => {
+          self.push(KeyEvent(KeyCode::F(1), ModKeys::empty()));
+          return;
+        }
+        'Q' => {
+          self.push(KeyEvent(KeyCode::F(2), ModKeys::empty()));
+          return;
+        }
+        'R' => {
+          self.push(KeyEvent(KeyCode::F(3), ModKeys::empty()));
+          return;
+        }
+        'S' => {
+          self.push(KeyEvent(KeyCode::F(4), ModKeys::empty()));
+          return;
+        }
+        _ => {}
+      }
+    }
+
     if c == '\x7f' {
       self.push(KeyEvent(KeyCode::Backspace, ModKeys::empty()));
     } else {
@@ -346,6 +396,7 @@ impl Perform for KeyCollector {
   }
 
   fn execute(&mut self, byte: u8) {
+    log::trace!("execute: {byte:#04x}");
     let event = match byte {
       0x00 => KeyEvent(KeyCode::Char(' '), ModKeys::CTRL), // Ctrl+Space / Ctrl+@
       0x09 => KeyEvent(KeyCode::Tab, ModKeys::empty()),    // Tab (Ctrl+I)
@@ -370,6 +421,9 @@ impl Perform for KeyCollector {
     _ignore: bool,
     action: char,
   ) {
+    log::trace!(
+      "CSI dispatch: params={params:?}, intermediates={intermediates:?}, action={action:?}"
+    );
     let params: Vec<u16> = params
       .iter()
       .map(|p| p.first().copied().unwrap_or(0))
@@ -481,16 +535,11 @@ impl Perform for KeyCollector {
   }
 
   fn esc_dispatch(&mut self, intermediates: &[u8], _ignore: bool, byte: u8) {
-    // SS3 sequences (ESC O P/Q/R/S for F1-F4)
-    if intermediates == [b'O'] {
-      let key = match byte {
-        b'P' => KeyCode::F(1),
-        b'Q' => KeyCode::F(2),
-        b'R' => KeyCode::F(3),
-        b'S' => KeyCode::F(4),
-        _ => return,
-      };
-      self.push(KeyEvent(key, ModKeys::empty()));
+    log::trace!("ESC dispatch: intermediates={intermediates:?}, byte={byte:#04x}");
+    // SS3 sequences
+    if byte == b'O' {
+      self.ss3_pending = true;
+      return;
     }
   }
 }

src/readline/tests.rs

@@ -2,10 +2,15 @@
 use std::os::fd::AsRawFd;
 
 use crate::{
-  readline::{Prompt, ShedVi},
+  readline::{Prompt, ShedVi, annotate_input},
   testutil::TestGuard,
 };
 
+fn assert_annotated(input: &str, expected: &str) {
+  let result = annotate_input(input);
+  assert_eq!(result, expected, "\nInput: {input:?}");
+}
+
 /// Tests for our vim logic emulation. Each test consists of an initial text, a sequence of keys to feed, and the expected final text and cursor position.
 macro_rules! vi_test {
     { $($name:ident: $input:expr => $op:expr => $expected_text:expr,$expected_cursor:expr);* } => {
@@ -26,6 +31,257 @@ macro_rules! vi_test {
     };
 }
 
+// ===================== Annotation Tests =====================
+
+#[test]
+fn annotate_simple_command() {
+  assert_annotated("echo hello", "\u{e101}echo\u{e11a} \u{e102}hello\u{e11a}");
+}
+
+#[test]
+fn annotate_pipeline() {
+  assert_annotated(
+    "ls | grep foo",
+    "\u{e100}ls\u{e11a} \u{e104}|\u{e11a} \u{e100}grep\u{e11a} \u{e102}foo\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_conjunction() {
+  assert_annotated(
+    "echo foo && echo bar",
+    "\u{e101}echo\u{e11a} \u{e102}foo\u{e11a} \u{e104}&&\u{e11a} \u{e101}echo\u{e11a} \u{e102}bar\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_redirect_output() {
+  assert_annotated(
+    "echo hello > file.txt",
+    "\u{e101}echo\u{e11a} \u{e102}hello\u{e11a} \u{e105}>\u{e11a} \u{e102}file.txt\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_redirect_append() {
+  assert_annotated(
+    "echo hello >> file.txt",
+    "\u{e101}echo\u{e11a} \u{e102}hello\u{e11a} \u{e105}>>\u{e11a} \u{e102}file.txt\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_redirect_input() {
+  assert_annotated(
+    "cat < file.txt",
+    "\u{e100}cat\u{e11a} \u{e105}<\u{e11a} \u{e102}file.txt\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_fd_redirect() {
+  assert_annotated("cmd 2>&1", "\u{e100}cmd\u{e11a} \u{e105}2>&1\u{e11a}");
+}
+
+#[test]
+fn annotate_variable_sub() {
+  assert_annotated(
+    "echo $HOME",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e10c}$HOME\u{e10d}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_variable_brace_sub() {
+  assert_annotated(
+    "echo ${HOME}",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e10c}${HOME}\u{e10d}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_command_sub() {
+  assert_annotated(
+    "echo $(ls)",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e10e}$(ls)\u{e10f}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_single_quoted_string() {
+  assert_annotated(
+    "echo 'hello world'",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e114}'hello world'\u{e115}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_double_quoted_string() {
+  assert_annotated(
+    "echo \"hello world\"",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e112}\"hello world\"\u{e113}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_assignment() {
+  assert_annotated("FOO=bar", "\u{e107}FOO=bar\u{e11a}");
+}
+
+#[test]
+fn annotate_assignment_with_command() {
+  assert_annotated(
+    "FOO=bar echo hello",
+    "\u{e107}FOO=bar\u{e11a} \u{e101}echo\u{e11a} \u{e102}hello\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_if_statement() {
+  assert_annotated(
+    "if true; then echo yes; fi",
+    "\u{e103}if\u{e11a} \u{e101}true\u{e11a}\u{e108}; \u{e11a}\u{e103}then\u{e11a} \u{e101}echo\u{e11a} \u{e102}yes\u{e11a}\u{e108}; \u{e11a}\u{e103}fi\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_for_loop() {
+  assert_annotated(
+    "for i in a b c; do echo $i; done",
+    "\u{e103}for\u{e11a} \u{e102}i\u{e11a} \u{e103}in\u{e11a} \u{e102}a\u{e11a} \u{e102}b\u{e11a} \u{e102}c\u{e11a}\u{e108}; \u{e11a}\u{e103}do\u{e11a} \u{e101}echo\u{e11a} \u{e102}\u{e10c}$i\u{e10d}\u{e11a}\u{e108}; \u{e11a}\u{e103}done\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_while_loop() {
+  assert_annotated(
+    "while true; do echo hello; done",
+    "\u{e103}while\u{e11a} \u{e101}true\u{e11a}\u{e108}; \u{e11a}\u{e103}do\u{e11a} \u{e101}echo\u{e11a} \u{e102}hello\u{e11a}\u{e108}; \u{e11a}\u{e103}done\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_case_statement() {
+  assert_annotated(
+    "case foo in bar) echo bar;; esac",
+    "\u{e103}case\u{e11a} \u{e102}foo\u{e11a} \u{e103}in\u{e11a} \u{e104}bar\u{e109})\u{e11a} \u{e101}echo\u{e11a} \u{e102}bar\u{e11a}\u{e108};; \u{e11a}\u{e103}esac\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_brace_group() {
+  assert_annotated(
+    "{ echo hello; }",
+    "\u{e104}{\u{e11a} \u{e101}echo\u{e11a} \u{e102}hello\u{e11a}\u{e108}; \u{e11a}\u{e104}}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_comment() {
+  assert_annotated(
+    "echo hello # this is a comment",
+    "\u{e101}echo\u{e11a} \u{e102}hello\u{e11a} \u{e106}# this is a comment\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_semicolon_sep() {
+  assert_annotated(
+    "echo foo; echo bar",
+    "\u{e101}echo\u{e11a} \u{e102}foo\u{e11a}\u{e108}; \u{e11a}\u{e101}echo\u{e11a} \u{e102}bar\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_escaped_char() {
+  assert_annotated(
+    "echo hello\\ world",
+    "\u{e101}echo\u{e11a} \u{e102}hello\\ world\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_glob() {
+  assert_annotated(
+    "ls *.txt",
+    "\u{e100}ls\u{e11a} \u{e102}\u{e117}*\u{e11a}.txt\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_heredoc_operator() {
+  assert_annotated(
+    "cat <<EOF",
+    "\u{e100}cat\u{e11a} \u{e105}<<\u{e11a}\u{e102}EOF\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_herestring_operator() {
+  assert_annotated(
+    "cat <<< hello",
+    "\u{e100}cat\u{e11a} \u{e105}<<<\u{e11a} \u{e102}hello\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_nested_command_sub() {
+  assert_annotated(
+    "echo $(echo $(ls))",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e10e}$(echo $(ls))\u{e10f}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_var_in_double_quotes() {
+  assert_annotated(
+    "echo \"hello $USER\"",
+    "\u{e101}echo\u{e11a} \u{e102}\u{e112}\"hello \u{e10c}$USER\u{e10d}\"\u{e113}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_func_def() {
+  assert_annotated(
+    "foo() { echo hello; }",
+    "\u{e103}foo()\u{e11a} \u{e104}{\u{e11a} \u{e101}echo\u{e11a} \u{e102}hello\u{e11a}\u{e108}; \u{e11a}\u{e104}}\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_negate() {
+  assert_annotated(
+    "! echo hello",
+    "\u{e104}!\u{e11a} \u{e101}echo\u{e11a} \u{e102}hello\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_or_conjunction() {
+  assert_annotated(
+    "false || echo fallback",
+    "\u{e101}false\u{e11a} \u{e104}||\u{e11a} \u{e101}echo\u{e11a} \u{e102}fallback\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_complex_pipeline() {
+  assert_annotated(
+    "cat file.txt | grep pattern | wc -l",
+    "\u{e100}cat\u{e11a} \u{e102}file.txt\u{e11a} \u{e104}|\u{e11a} \u{e100}grep\u{e11a} \u{e102}pattern\u{e11a} \u{e104}|\u{e11a} \u{e100}wc\u{e11a} \u{e102}-l\u{e11a}",
+  );
+}
+
+#[test]
+fn annotate_multiple_redirects() {
+  assert_annotated(
+    "cmd > out.txt 2> err.txt",
+    "\u{e100}cmd\u{e11a} \u{e105}>\u{e11a} \u{e102}out.txt\u{e11a} \u{e105}2>\u{e11a} \u{e102}err.txt\u{e11a}",
+  );
+}
+
+// ===================== Vi Tests =====================
+
 fn test_vi(initial: &str) -> (ShedVi, TestGuard) {
   let g = TestGuard::new();
   let prompt = Prompt::default();
@@ -233,3 +489,30 @@ vi_test! {
   vi_indent_cursor_pos : "echo foo"               => ">>"           => "\techo foo", 1;
   vi_join_indent_lines : "echo foo\n\t\techo bar" => "J"        => "echo foo echo bar", 8
 }
+
+#[test]
+fn vi_auto_indent() {
+  let (mut vi, _g) = test_vi("");
+
+  // Type each line and press Enter separately so auto-indent triggers
+  let lines = [
+    "func() {",
+    "case foo in",
+    "bar)",
+    "while true; do",
+    "echo foo \\\rbar \\\rbiz \\\rbazz\rbreak\rdone\r;;\resac\r}",
+  ];
+
+  for (i, line) in lines.iter().enumerate() {
+    vi.feed_bytes(line.as_bytes());
+    if i != lines.len() - 1 {
+      vi.feed_bytes(b"\r");
+    }
+    vi.process_input().unwrap();
+  }
+
+  assert_eq!(
+    vi.editor.as_str(),
+    "func() {\n\tcase foo in\n\t\tbar)\n\t\t\twhile true; do\n\t\t\t\techo foo \\\n\t\t\t\t\tbar \\\n\t\t\t\t\tbiz \\\n\t\t\t\t\tbazz\n\t\t\t\tbreak\n\t\t\tdone\n\t\t;;\n\tesac\n}"
+  );
+}

src/shopt.rs

@@ -146,6 +146,7 @@ pub struct ShOptCore {
   pub bell_enabled: bool,
   pub max_recurse_depth: usize,
   pub xpg_echo: bool,
+  pub noclobber: bool,
 }
 
 impl ShOptCore {
@@ -238,6 +239,15 @@ impl ShOptCore {
         };
         self.xpg_echo = val;
       }
+      "noclobber" => {
+        let Ok(val) = val.parse::<bool>() else {
+          return Err(ShErr::simple(
+            ShErrKind::SyntaxErr,
+            "shopt: expected 'true' or 'false' for noclobber value",
+          ));
+        };
+        self.noclobber = val;
+      }
       _ => {
         return Err(ShErr::simple(
           ShErrKind::SyntaxErr,
@@ -304,6 +314,12 @@ impl ShOptCore {
         output.push_str(&format!("{}", self.xpg_echo));
         Ok(Some(output))
       }
+      "noclobber" => {
+        let mut output =
+          String::from("Prevent > from overwriting existing files (use >| to override)\n");
+        output.push_str(&format!("{}", self.noclobber));
+        Ok(Some(output))
+      }
       _ => Err(ShErr::simple(
         ShErrKind::SyntaxErr,
         format!("shopt: Unexpected 'core' option '{query}'"),
@@ -327,6 +343,7 @@ impl Display for ShOptCore {
     output.push(format!("bell_enabled = {}", self.bell_enabled));
     output.push(format!("max_recurse_depth = {}", self.max_recurse_depth));
     output.push(format!("xpg_echo = {}", self.xpg_echo));
+    output.push(format!("noclobber = {}", self.noclobber));
 
     let final_output = output.join("\n");
 
@@ -346,6 +363,7 @@ impl Default for ShOptCore {
       bell_enabled: true,
       max_recurse_depth: 1000,
       xpg_echo: false,
+      noclobber: false,
     }
   }
 }
@@ -589,6 +607,7 @@ mod tests {
       bell_enabled,
       max_recurse_depth,
       xpg_echo,
+      noclobber,
     } = ShOptCore::default();
     // If a field is added to the struct, this destructure fails to compile.
     let _ = (
@@ -601,6 +620,7 @@ mod tests {
       bell_enabled,
       max_recurse_depth,
       xpg_echo,
+      noclobber,
     );
   }
 

src/state.rs

@@ -1330,6 +1330,15 @@ impl VarTab {
         .get(&ShellParam::Status)
         .map(|s| s.to_string())
         .unwrap_or("0".into()),
+      ShellParam::AllArgsStr => {
+        let ifs = get_separator();
+        self
+          .params
+          .get(&ShellParam::AllArgs)
+          .map(|s| s.replace(markers::ARG_SEP, &ifs).to_string())
+          .unwrap_or_default()
+      }
+
       _ => self
         .params
         .get(&param)
@@ -1842,6 +1851,15 @@ pub fn change_dir<P: AsRef<Path>>(dir: P) -> ShResult<()> {
   Ok(())
 }
 
+pub fn get_separator() -> String {
+  env::var("IFS")
+    .unwrap_or(String::from(" "))
+    .chars()
+    .next()
+    .unwrap()
+    .to_string()
+}
+
 pub fn get_status() -> i32 {
   read_vars(|v| v.get_param(ShellParam::Status))
     .parse::<i32>()

src/testutil.rs

@@ -98,7 +98,7 @@ impl TestGuard {
     }
   }
 
-  pub fn pty_slave(&self) -> BorrowedFd {
+  pub fn pty_slave(&self) -> BorrowedFd<'_> {
     unsafe { BorrowedFd::borrow_raw(self.pty_slave.as_raw_fd()) }
   }
 
@@ -191,7 +191,7 @@ impl crate::parse::Node {
       if offender.is_none()
         && expected_rule
           .as_ref()
-          .map_or(true, |e| *e != s.class.as_nd_kind())
+          .is_none_or(|e| *e != s.class.as_nd_kind())
       {
         offender = Some((s.class.as_nd_kind(), expected_rule));
       } else if offender.is_none() {