feat(ux): rerun command pane (#1787)

* chore(config): default kdl keybindings config

* tests

* work

* refactor(config): move stuff around

* work

* tab merge layout

* work

* work

* layouts working

* work

* layout tests

* work

* work

* feat(parsing): kdl layouts without config

* refactor(kdl): move stuff around

* work

* tests(layout): add cases and fix bugs

* work

* fix(kdl): various bugs

* chore(layouts): move all layouts to kdl

* feat(kdl): shared keybidns

* fix(layout): do not count fixed panes toward percentile

* fix(keybinds): missing keybinds and actions

* fix(config): adjust default tips

* refactor(config): move stuff around

* fix(tests): make e2e tests pass

* fix(kdl): add verbose parsing errors

* fix(kdl): focused tab

* fix(layout): corret default_tab_template behavior

* style(code): fix compile warnings

* feat(cli): send actions through the cli

* fix(cli): exit only when action is done

* fix(cli): open embedded pane from floating pane

* fix(cli): send actions to other sessions

* feat(cli): command alias

* feat(converter): convert old config

* feat(converter): convert old layout and theme files

* feat(kdl): pretty errors

* feat(client): convert old YAML files on startup

* fix: various bugs and styling issues

* fix: e2e tests

* fix(screen): propagate errors after merge

* style(clippy): lower clippy level

* fix(tests): own session_name variable

* style(fmt): rustfmt

* fix(cli): various action fixes

* style(fmt): rustfmt

* fix(themes): loading of theme files

* style(fmt): rustfmt

* fix(tests): theme fixtures

* fix(layouts): better errors on unknown nodes

* fix(kdl): clarify valid node terminator error

* fix(e2e): adjust close tab test

* fix(e2e): adjust close tab test again

* style(code): cleanup some comments

* get command panes not to exit on command exit

* separate terminal pane_ids from raw_fds

* render frame according to exit status

* re-run command on enter and close pane on ctrl-c

* proper error when command is not found

* make ui nicer

* initial pane title for command panes

* fix pane override bug

* reap terminal_ids from os_input_output on pane close

* bool floating flag

* some ui tweaks

* fix tests

* make rustfmt happy

* e2e test for command pane

* fix various concurrency issues

* rename command to run in the cli

* rustfmt

* style(fmt): rustfmt

* fix(e2e): command => run

* fix(e2e): command => run in snapshot too!

src/main.rs

@@ -19,7 +19,7 @@ fn main() {
             commands::send_action_to_session(cli_action, opts.session);
             std::process::exit(0);
         }
-        if let Some(Command::Sessions(Sessions::Command {
+        if let Some(Command::Sessions(Sessions::Run {
             command,
             direction,
             cwd,

src/tests/e2e/cases.rs

@@ -13,6 +13,7 @@ use super::remote_runner::{RemoteRunner, RemoteTerminal, Step};
 pub const QUIT: [u8; 1] = [17]; // ctrl-q
 pub const ESC: [u8; 1] = [27];
 pub const ENTER: [u8; 1] = [10]; // char '\n'
+pub const SPACE: [u8; 1] = [32];
 pub const LOCK_MODE: [u8; 1] = [7]; // ctrl-g
 
 pub const MOVE_FOCUS_LEFT_IN_NORMAL_MODE: [u8; 2] = [27, 104]; // alt-h
@@ -1876,3 +1877,93 @@ pub fn undo_rename_pane() {
     };
     assert_snapshot!(last_snapshot);
 }
+
+#[test]
+#[ignore]
+pub fn send_command_through_the_cli() {
+    // here we test the following flow:
+    // - send a command through the cli to run a bash script in a temporary folder
+    // - have it open a "command pane" that can be re-run with Enter
+    // - press Enter in the command pane to re-run the script
+    //
+    // the script appends the word "foo" to a temporary file and then `cat`s that file,
+    // so when we press "Enter", it will run again and we'll see two "foo"s one after the other,
+    // that's how we know the whole flow is working
+    let fake_win_size = Size {
+        cols: 120,
+        rows: 24,
+    };
+    let mut test_attempts = 10;
+    let last_snapshot = loop {
+        RemoteRunner::kill_running_sessions(fake_win_size);
+        let mut runner = RemoteRunner::new(fake_win_size)
+            .add_step(Step {
+                name: "Run command through the cli",
+                instruction: |mut remote_terminal: RemoteTerminal| -> bool {
+                    let mut step_is_complete = false;
+                    if remote_terminal.status_bar_appears()
+                        && remote_terminal.cursor_position_is(3, 2)
+                    {
+                        let fixture_folder = remote_terminal.path_to_fixture_folder();
+                        remote_terminal.send_command_through_the_cli(&format!(
+                            "{}/append-echo-script.sh",
+                            fixture_folder
+                        ));
+                        step_is_complete = true;
+                    }
+                    step_is_complete
+                },
+            })
+            .add_step(Step {
+                name: "Wait for command to run",
+                instruction: |mut remote_terminal: RemoteTerminal| -> bool {
+                    let mut step_is_complete = false;
+                    if remote_terminal.snapshot_contains("<Ctrl-c>")
+                        && remote_terminal.cursor_position_is(61, 3)
+                    {
+                        remote_terminal.send_key(&SPACE); // re-run script - here we use SPACE
+                                                          // instead of the default ENTER because
+                                                          // sending ENTER over SSH can be a little
+                                                          // problematic (read: I couldn't get it
+                                                          // to pass consistently)
+                        step_is_complete = true
+                    }
+                    step_is_complete
+                },
+            })
+            .add_step(Step {
+                name: "Wait for script to run again",
+                instruction: |mut remote_terminal: RemoteTerminal| -> bool {
+                    let mut step_is_complete = false;
+                    if remote_terminal.snapshot_contains("<Ctrl-c>")
+                        && remote_terminal.cursor_position_is(61, 4)
+                    {
+                        step_is_complete = true
+                    }
+                    step_is_complete
+                },
+            });
+        runner.run_all_steps();
+
+        let last_snapshot = runner.take_snapshot_after(Step {
+            name: "Wait for script to run twice",
+            instruction: |remote_terminal: RemoteTerminal| -> bool {
+                let mut step_is_complete = false;
+                if remote_terminal.snapshot_contains("foo")
+                    && remote_terminal.cursor_position_is(61, 4)
+                {
+                    step_is_complete = true
+                }
+                step_is_complete
+            },
+        });
+
+        if runner.test_timed_out && test_attempts > 0 {
+            test_attempts -= 1;
+            continue;
+        } else {
+            break last_snapshot;
+        }
+    };
+    assert_snapshot!(last_snapshot);
+}

src/tests/e2e/remote_runner.rs

@@ -64,6 +64,8 @@ fn stop_zellij(channel: &mut ssh2::Channel) {
         .write_all(b"find /tmp | grep status-bar-tips | xargs rm\n")
         .unwrap();
     channel.write_all(b"killall -KILL zellij\n").unwrap();
+    channel.write_all(b"rm -rf /tmp/*\n").unwrap(); // remove temporary artifacts from previous
+                                                    // tests
 }
 
 fn start_zellij(channel: &mut ssh2::Channel) {
@@ -198,6 +200,7 @@ fn read_from_channel(
                     sixel_image_store,
                     Rc::new(RefCell::new(Palette::default())),
                     Rc::new(RefCell::new(HashMap::new())),
+                    None,
                 ); // 0 is the pane index
                 loop {
                     if !should_keep_running.load(Ordering::SeqCst) {
@@ -339,6 +342,16 @@ impl RemoteTerminal {
         channel.flush().unwrap();
         std::thread::sleep(std::time::Duration::from_secs(1)); // wait until Zellij stops parsing startup ANSI codes from the terminal STDIN
     }
+    pub fn send_command_through_the_cli(&mut self, command: &str) {
+        let mut channel = self.channel.lock().unwrap();
+        channel
+            .write_all(format!("{} run \"{}\"\n", ZELLIJ_EXECUTABLE_LOCATION, command).as_bytes())
+            .unwrap();
+        channel.flush().unwrap();
+    }
+    pub fn path_to_fixture_folder(&self) -> String {
+        ZELLIJ_FIXTURE_PATH.to_string()
+    }
     pub fn load_fixture(&mut self, name: &str) {
         let mut channel = self.channel.lock().unwrap();
         channel

src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_command_through_the_cli.snap

@@ -0,0 +1,29 @@
+---
+source: src/tests/e2e/cases.rs
+assertion_line: 1968
+expression: last_snapshot
+---
+ Zellij (e2e-test)  Tab #1                                                                                            
+┌ Pane #1 ─────────────────────────────────────────────────┐┌ /usr/src/zellij/fixtures/append-echo-script.sh ──────────┐
+│$ /usr/src/zellij/x86_64-unknown-linux-musl/release/zellij││foo                                                       │
+│ run "/usr/src/zellij/fixtures/append-echo-script.sh"     ││foo                                                       │
+│$                                                         ││█                                                         │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+│                                                          ││                                                          │
+└──────────────────────────────────────────────────────────┘└ [ EXIT CODE: 0 ] <ENTER> to re-run, <Ctrl-c> to exit ────┘
+ Ctrl + <g> LOCK  <p> PANE  <t> TAB  <n> RESIZE  <h> MOVE  <s> SEARCH  <o> SESSION  <q> QUIT           
+ Tip: Alt + <n> => new pane. Alt + <←↓↑→> or Alt + <hjkl> => navigate. Alt + <+|-> => resize pane.                      

src/tests/fixtures/append-echo-script.sh

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+echo foo >> /tmp/foo && cat /tmp/foo

zellij-server/src/os_input_output.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::collections::{BTreeMap, HashMap, HashSet};
 use std::{fs::File, io::Write};
 
 use crate::panes::PaneId;
@@ -39,7 +39,7 @@ pub use nix::unistd::Pid;
 
 use crate::ClientId;
 
-pub(crate) fn set_terminal_size_using_fd(fd: RawFd, columns: u16, rows: u16) {
+fn set_terminal_size_using_fd(fd: RawFd, columns: u16, rows: u16) {
     // TODO: do this with the nix ioctl
     use libc::ioctl;
     use libc::TIOCSWINSZ;
@@ -61,18 +61,19 @@ pub(crate) fn set_terminal_size_using_fd(fd: RawFd, columns: u16, rows: u16) {
 
 /// Handle some signals for the child process. This will loop until the child
 /// process exits.
-fn handle_command_exit(mut child: Child) {
+fn handle_command_exit(mut child: Child) -> Option<i32> {
+    // returns the exit status, if any
     let mut should_exit = false;
     let mut attempts = 3;
     let mut signals = signal_hook::iterator::Signals::new(&[SIGINT, SIGTERM]).unwrap();
     'handle_exit: loop {
         // test whether the child process has exited
         match child.try_wait() {
-            Ok(Some(_status)) => {
+            Ok(Some(status)) => {
                 // if the child process has exited, break outside of the loop
                 // and exit this function
                 // TODO: handle errors?
-                break 'handle_exit;
+                break 'handle_exit status.code();
             },
             Ok(None) => {
                 ::std::thread::sleep(::std::time::Duration::from_millis(10));
@@ -94,50 +95,80 @@ fn handle_command_exit(mut child: Child) {
         } else {
             // when I say whoa, I mean WHOA!
             let _ = child.kill();
-            break 'handle_exit;
+            break 'handle_exit None;
         }
     }
 }
 
+fn command_exists(cmd: &RunCommand) -> bool {
+    let command = &cmd.command;
+    match cmd.cwd.as_ref() {
+        Some(cwd) => {
+            if cwd.join(&command).exists() {
+                return true;
+            }
+        },
+        None => {
+            if command.exists() {
+                return true;
+            }
+        },
+    }
+
+    if let Some(paths) = env::var_os("PATH") {
+        for path in env::split_paths(&paths) {
+            if path.join(command).exists() {
+                return true;
+            }
+        }
+    }
+    false
+}
+
 fn handle_openpty(
     open_pty_res: OpenptyResult,
     cmd: RunCommand,
-    quit_cb: Box<dyn Fn(PaneId) + Send>,
-) -> (RawFd, RawFd) {
+    quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
+    terminal_id: u32,
+) -> Result<(RawFd, RawFd), SpawnTerminalError> {
     // primary side of pty and child fd
     let pid_primary = open_pty_res.master;
     let pid_secondary = open_pty_res.slave;
 
-    let mut child = unsafe {
-        let command = &mut Command::new(cmd.command);
-        if let Some(current_dir) = cmd.cwd {
-            if current_dir.exists() {
-                command.current_dir(current_dir);
-            }
-        }
-        command
-            .args(&cmd.args)
-            .pre_exec(move || -> std::io::Result<()> {
-                if libc::login_tty(pid_secondary) != 0 {
-                    panic!("failed to set controlling terminal");
+    if command_exists(&cmd) {
+        let mut child = unsafe {
+            let cmd = cmd.clone();
+            let command = &mut Command::new(cmd.command);
+            if let Some(current_dir) = cmd.cwd {
+                if current_dir.exists() {
+                    command.current_dir(current_dir);
                 }
-                close_fds::close_open_fds(3, &[]);
-                Ok(())
-            })
-            .spawn()
-            .expect("failed to spawn")
-    };
+            }
+            command
+                .args(&cmd.args)
+                .pre_exec(move || -> std::io::Result<()> {
+                    if libc::login_tty(pid_secondary) != 0 {
+                        panic!("failed to set controlling terminal");
+                    }
+                    close_fds::close_open_fds(3, &[]);
+                    Ok(())
+                })
+                .spawn()
+                .expect("failed to spawn")
+        };
 
-    let child_id = child.id();
-    std::thread::spawn(move || {
-        child.wait().unwrap();
-        handle_command_exit(child);
-        let _ = nix::unistd::close(pid_primary);
-        let _ = nix::unistd::close(pid_secondary);
-        quit_cb(PaneId::Terminal(pid_primary));
-    });
+        let child_id = child.id();
+        std::thread::spawn(move || {
+            child.wait().unwrap();
+            let exit_status = handle_command_exit(child);
+            let _ = nix::unistd::close(pid_secondary);
+            quit_cb(PaneId::Terminal(terminal_id), exit_status, cmd);
+        });
 
-    (pid_primary, child_id as RawFd)
+        Ok((pid_primary, child_id as RawFd))
+    } else {
+        Err(SpawnTerminalError::CommandNotFound(terminal_id))
+    }
 }
 
 /// Spawns a new terminal from the parent terminal with [`termios`](termios::Termios)
@@ -147,16 +178,20 @@ fn handle_terminal(
     cmd: RunCommand,
     failover_cmd: Option<RunCommand>,
     orig_termios: termios::Termios,
-    quit_cb: Box<dyn Fn(PaneId) + Send>,
-) -> (RawFd, RawFd) {
-    // Create a pipe to allow the child the communicate the shell's pid to it's
+    quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>,
+    terminal_id: u32,
+) -> Result<(RawFd, RawFd), SpawnTerminalError> {
+    // Create a pipe to allow the child the communicate the shell's pid to its
     // parent.
     match openpty(None, Some(&orig_termios)) {
-        Ok(open_pty_res) => handle_openpty(open_pty_res, cmd, quit_cb),
+        Ok(open_pty_res) => handle_openpty(open_pty_res, cmd, quit_cb, terminal_id),
         Err(e) => match failover_cmd {
-            Some(failover_cmd) => handle_terminal(failover_cmd, None, orig_termios, quit_cb),
+            Some(failover_cmd) => {
+                handle_terminal(failover_cmd, None, orig_termios, quit_cb, terminal_id)
+            },
             None => {
-                panic!("failed to start pty{:?}", e);
+                log::error!("Failed to start pty: {:?}", e);
+                Err(SpawnTerminalError::FailedToStartPty)
             },
         },
     }
@@ -192,12 +227,15 @@ fn separate_command_arguments(command: &mut PathBuf, args: &mut Vec<String>) {
 ///
 /// This function will panic if both the `EDITOR` and `VISUAL` environment variables are not
 /// set.
-pub fn spawn_terminal(
+fn spawn_terminal(
     terminal_action: TerminalAction,
     orig_termios: termios::Termios,
-    quit_cb: Box<dyn Fn(PaneId) + Send>,
+    quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit_status
     default_editor: Option<PathBuf>,
-) -> Result<(RawFd, RawFd), &'static str> {
+    terminal_id: u32,
+) -> Result<(RawFd, RawFd), SpawnTerminalError> {
+    // returns the terminal_id, the primary fd and the
+    // secondary fd
     let mut failover_cmd_args = None;
     let cmd = match terminal_action {
         TerminalAction::OpenFile(file_to_open, line_number) => {
@@ -205,9 +243,7 @@ pub fn spawn_terminal(
                 && env::var("EDITOR").is_err()
                 && env::var("VISUAL").is_err()
             {
-                return Err(
-                    "No Editor found, consider setting a path to one in $EDITOR or $VISUAL",
-                );
+                return Err(SpawnTerminalError::NoEditorFound);
             }
 
             let mut command = default_editor.unwrap_or_else(|| {
@@ -239,6 +275,7 @@ pub fn spawn_terminal(
                 command,
                 args,
                 cwd: None,
+                hold_on_close: false,
             }
         },
         TerminalAction::RunCommand(command) => command,
@@ -251,13 +288,52 @@ pub fn spawn_terminal(
         None
     };
 
-    Ok(handle_terminal(cmd, failover_cmd, orig_termios, quit_cb))
+    handle_terminal(cmd, failover_cmd, orig_termios, quit_cb, terminal_id)
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum SpawnTerminalError {
+    CommandNotFound(u32), // u32 is the terminal id
+    NoEditorFound,
+    NoMoreTerminalIds,
+    FailedToStartPty,
+    GenericSpawnError(&'static str),
+}
+
+impl std::fmt::Display for SpawnTerminalError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        match self {
+            SpawnTerminalError::CommandNotFound(terminal_id) => {
+                write!(f, "Command not found for terminal_id: {}", terminal_id)
+            },
+            SpawnTerminalError::NoEditorFound => {
+                write!(
+                    f,
+                    "No Editor found, consider setting a path to one in $EDITOR or $VISUAL"
+                )
+            },
+            SpawnTerminalError::NoMoreTerminalIds => {
+                write!(f, "No more terminal ids left to allocate.")
+            },
+            SpawnTerminalError::FailedToStartPty => {
+                write!(f, "Failed to start pty")
+            },
+            SpawnTerminalError::GenericSpawnError(msg) => {
+                write!(f, "{}", msg)
+            },
+        }
+    }
 }
 
 #[derive(Clone)]
 pub struct ServerOsInputOutput {
     orig_termios: Arc<Mutex<termios::Termios>>,
     client_senders: Arc<Mutex<HashMap<ClientId, IpcSenderWithContext<ServerToClientMsg>>>>,
+    terminal_id_to_raw_fd: Arc<Mutex<BTreeMap<u32, Option<RawFd>>>>, // A value of None means the
+                                                                     // terminal_id exists but is
+                                                                     // not connected to an fd (eg.
+                                                                     // a command pane with a
+                                                                     // non-existing command)
 }
 
 // async fn in traits is not supported by rust, so dtolnay's excellent async_trait macro is being
@@ -291,25 +367,24 @@ impl AsyncReader for RawFdAsyncReader {
 /// The `ServerOsApi` trait represents an abstract interface to the features of an operating system that
 /// Zellij server requires.
 pub trait ServerOsApi: Send + Sync {
-    /// Sets the size of the terminal associated to file descriptor `fd`.
-    fn set_terminal_size_using_fd(&self, fd: RawFd, cols: u16, rows: u16);
+    fn set_terminal_size_using_terminal_id(&self, id: u32, cols: u16, rows: u16);
     /// Spawn a new terminal, with a terminal action. The returned tuple contains the master file
     /// descriptor of the forked pseudo terminal and a [ChildId] struct containing process id's for
     /// the forked child process.
     fn spawn_terminal(
         &self,
         terminal_action: TerminalAction,
-        quit_cb: Box<dyn Fn(PaneId) + Send>,
+        quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
         default_editor: Option<PathBuf>,
-    ) -> Result<(RawFd, RawFd), &'static str>;
+    ) -> Result<(u32, RawFd, RawFd), SpawnTerminalError>;
     /// Read bytes from the standard output of the virtual terminal referred to by `fd`.
     fn read_from_tty_stdout(&self, fd: RawFd, buf: &mut [u8]) -> Result<usize, nix::Error>;
     /// Creates an `AsyncReader` that can be used to read from `fd` in an async context
     fn async_file_reader(&self, fd: RawFd) -> Box<dyn AsyncReader>;
     /// Write bytes to the standard input of the virtual terminal referred to by `fd`.
-    fn write_to_tty_stdin(&self, fd: RawFd, buf: &[u8]) -> Result<usize, nix::Error>;
+    fn write_to_tty_stdin(&self, terminal_id: u32, buf: &[u8]) -> Result<usize, nix::Error>;
     /// Wait until all output written to the object referred to by `fd` has been transmitted.
-    fn tcdrain(&self, fd: RawFd) -> Result<(), nix::Error>;
+    fn tcdrain(&self, terminal_id: u32) -> Result<(), nix::Error>;
     /// Terminate the process with process ID `pid`. (SIGTERM)
     fn kill(&self, pid: Pid) -> Result<(), nix::Error>;
     /// Terminate the process with process ID `pid`. (SIGKILL)
@@ -332,27 +407,78 @@ pub trait ServerOsApi: Send + Sync {
     fn get_cwd(&self, pid: Pid) -> Option<PathBuf>;
     /// Writes the given buffer to a string
     fn write_to_file(&mut self, buf: String, file: Option<String>);
+
+    fn re_run_command_in_terminal(
+        &self,
+        terminal_id: u32,
+        run_command: RunCommand,
+        quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
+    ) -> Result<(RawFd, RawFd), SpawnTerminalError>;
+    fn clear_terminal_id(&self, terminal_id: u32);
 }
 
 impl ServerOsApi for ServerOsInputOutput {
-    fn set_terminal_size_using_fd(&self, fd: RawFd, cols: u16, rows: u16) {
-        if cols > 0 && rows > 0 {
-            set_terminal_size_using_fd(fd, cols, rows);
+    fn set_terminal_size_using_terminal_id(&self, id: u32, cols: u16, rows: u16) {
+        match self.terminal_id_to_raw_fd.lock().unwrap().get(&id) {
+            Some(Some(fd)) => {
+                if cols > 0 && rows > 0 {
+                    set_terminal_size_using_fd(*fd, cols, rows);
+                }
+            },
+            _ => {
+                log::error!("Failed to find terminal fd for id: {id}, so cannot resize terminal");
+            },
         }
     }
     fn spawn_terminal(
         &self,
         terminal_action: TerminalAction,
-        quit_cb: Box<dyn Fn(PaneId) + Send>,
+        quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
         default_editor: Option<PathBuf>,
-    ) -> Result<(RawFd, RawFd), &'static str> {
+    ) -> Result<(u32, RawFd, RawFd), SpawnTerminalError> {
         let orig_termios = self.orig_termios.lock().unwrap();
-        spawn_terminal(
-            terminal_action,
-            orig_termios.clone(),
-            quit_cb,
-            default_editor,
-        )
+        let mut terminal_id = None;
+        {
+            let current_ids: HashSet<u32> = self
+                .terminal_id_to_raw_fd
+                .lock()
+                .unwrap()
+                .keys()
+                .copied()
+                .collect();
+            for i in 0..u32::MAX {
+                let i = i as u32;
+                if !current_ids.contains(&i) {
+                    terminal_id = Some(i);
+                    break;
+                }
+            }
+        }
+        match terminal_id {
+            Some(terminal_id) => {
+                self.terminal_id_to_raw_fd
+                    .lock()
+                    .unwrap()
+                    .insert(terminal_id, None);
+                match spawn_terminal(
+                    terminal_action,
+                    orig_termios.clone(),
+                    quit_cb,
+                    default_editor,
+                    terminal_id,
+                ) {
+                    Ok((pid_primary, pid_secondary)) => {
+                        self.terminal_id_to_raw_fd
+                            .lock()
+                            .unwrap()
+                            .insert(terminal_id, Some(pid_primary));
+                        Ok((terminal_id, pid_primary, pid_secondary))
+                    },
+                    Err(e) => Err(e),
+                }
+            },
+            None => Err(SpawnTerminalError::NoMoreTerminalIds),
+        }
     }
     fn read_from_tty_stdout(&self, fd: RawFd, buf: &mut [u8]) -> Result<usize, nix::Error> {
         unistd::read(fd, buf)
@@ -360,11 +486,25 @@ impl ServerOsApi for ServerOsInputOutput {
     fn async_file_reader(&self, fd: RawFd) -> Box<dyn AsyncReader> {
         Box::new(RawFdAsyncReader::new(fd))
     }
-    fn write_to_tty_stdin(&self, fd: RawFd, buf: &[u8]) -> Result<usize, nix::Error> {
-        unistd::write(fd, buf)
+    fn write_to_tty_stdin(&self, terminal_id: u32, buf: &[u8]) -> Result<usize, nix::Error> {
+        match self.terminal_id_to_raw_fd.lock().unwrap().get(&terminal_id) {
+            Some(Some(fd)) => unistd::write(*fd, buf),
+            _ => {
+                // TODO: propagate this error
+                log::error!("Failed to write to terminal with {terminal_id} - could not find its file descriptor");
+                Ok(0)
+            },
+        }
     }
-    fn tcdrain(&self, fd: RawFd) -> Result<(), nix::Error> {
-        termios::tcdrain(fd)
+    fn tcdrain(&self, terminal_id: u32) -> Result<(), nix::Error> {
+        match self.terminal_id_to_raw_fd.lock().unwrap().get(&terminal_id) {
+            Some(Some(fd)) => termios::tcdrain(*fd),
+            _ => {
+                // TODO: propagate this error
+                log::error!("Failed to tcdrain to terminal with {terminal_id} - could not find its file descriptor");
+                Ok(())
+            },
+        }
     }
     fn box_clone(&self) -> Box<dyn ServerOsApi> {
         Box::new((*self).clone())
@@ -430,6 +570,37 @@ impl ServerOsApi for ServerOsInputOutput {
             log::error!("could not write to file: {}", e);
         }
     }
+    fn re_run_command_in_terminal(
+        &self,
+        terminal_id: u32,
+        run_command: RunCommand,
+        quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
+    ) -> Result<(RawFd, RawFd), SpawnTerminalError> {
+        let orig_termios = self.orig_termios.lock().unwrap();
+        let default_editor = None; // no need for a default editor when running an explicit command
+        match spawn_terminal(
+            TerminalAction::RunCommand(run_command),
+            orig_termios.clone(),
+            quit_cb,
+            default_editor,
+            terminal_id,
+        ) {
+            Ok((pid_primary, pid_secondary)) => {
+                self.terminal_id_to_raw_fd
+                    .lock()
+                    .unwrap()
+                    .insert(terminal_id, Some(pid_primary));
+                Ok((pid_primary, pid_secondary))
+            },
+            Err(e) => Err(e),
+        }
+    }
+    fn clear_terminal_id(&self, terminal_id: u32) {
+        self.terminal_id_to_raw_fd
+            .lock()
+            .unwrap()
+            .remove(&terminal_id);
+    }
 }
 
 impl Clone for Box<dyn ServerOsApi> {
@@ -444,6 +615,7 @@ pub fn get_server_os_input() -> Result<ServerOsInputOutput, nix::Error> {
     Ok(ServerOsInputOutput {
         orig_termios,
         client_senders: Arc::new(Mutex::new(HashMap::new())),
+        terminal_id_to_raw_fd: Arc::new(Mutex::new(BTreeMap::new())),
     })
 }
 

zellij-server/src/panes/floating_panes/mod.rs

@@ -17,15 +17,16 @@ use std::rc::Rc;
 use std::time::Instant;
 use zellij_utils::{
     data::{ModeInfo, Style},
+    input::command::RunCommand,
     pane_size::{Offset, PaneGeom, Size, Viewport},
 };
 
 macro_rules! resize_pty {
     ($pane:expr, $os_input:expr) => {
         if let PaneId::Terminal(ref pid) = $pane.pid() {
-            // FIXME: This `set_terminal_size_using_fd` call would be best in
+            // FIXME: This `set_terminal_size_using_terminal_id` call would be best in
             // `TerminalPane::reflow_lines`
-            $os_input.set_terminal_size_using_fd(
+            $os_input.set_terminal_size_using_terminal_id(
                 *pid,
                 $pane.get_content_columns() as u16,
                 $pane.get_content_rows() as u16,
@@ -150,6 +151,16 @@ impl FloatingPanes {
         self.desired_pane_positions.remove(&pane_id);
         self.panes.remove(&pane_id)
     }
+    pub fn hold_pane(
+        &mut self,
+        pane_id: PaneId,
+        exit_status: Option<i32>,
+        run_command: RunCommand,
+    ) {
+        self.panes
+            .get_mut(&pane_id)
+            .map(|p| p.hold(exit_status, run_command));
+    }
     pub fn get(&self, pane_id: &PaneId) -> Option<&Box<dyn Pane>> {
         self.panes.get(pane_id)
     }

zellij-server/src/panes/grid.rs

@@ -1504,7 +1504,7 @@ impl Grid {
     pub fn mark_for_rerender(&mut self) {
         self.should_render = true;
     }
-    fn reset_terminal_state(&mut self) {
+    pub fn reset_terminal_state(&mut self) {
         self.lines_above = VecDeque::with_capacity(*SCROLL_BUFFER_SIZE.get().unwrap());
         self.lines_below = vec![];
         self.viewport = vec![Row::new(self.width).canonical()];

zellij-server/src/panes/plugin_pane.rs

@@ -113,10 +113,6 @@ impl Pane for PluginPane {
     fn cursor_coordinates(&self) -> Option<(usize, usize)> {
         None
     }
-    fn adjust_input_to_terminal(&self, _input_bytes: Vec<u8>) -> Vec<u8> {
-        // noop
-        vec![]
-    }
     fn position_and_size(&self) -> PaneGeom {
         self.geom
     }

zellij-server/src/panes/terminal_pane.rs

@@ -6,14 +6,14 @@ use crate::panes::{
 };
 use crate::panes::{AnsiCode, LinkHandler};
 use crate::pty::VteBytes;
-use crate::tab::Pane;
+use crate::tab::{AdjustedInput, Pane};
 use crate::ClientId;
 use std::cell::RefCell;
 use std::collections::{HashMap, HashSet};
 use std::fmt::Debug;
-use std::os::unix::io::RawFd;
 use std::rc::Rc;
 use std::time::{self, Instant};
+use zellij_utils::input::command::RunCommand;
 use zellij_utils::pane_size::Offset;
 use zellij_utils::{
     data::{InputMode, Palette, PaletteColor, Style},
@@ -37,6 +37,10 @@ const HOME_KEY: &[u8] = &[27, 91, 72];
 const END_KEY: &[u8] = &[27, 91, 70];
 const BRACKETED_PASTE_BEGIN: &[u8] = &[27, 91, 50, 48, 48, 126];
 const BRACKETED_PASTE_END: &[u8] = &[27, 91, 50, 48, 49, 126];
+const ENTER_NEWLINE: &[u8] = &[10];
+const ENTER_CARRIAGE_RETURN: &[u8] = &[13];
+const SPACE: &[u8] = &[32];
+const CTRL_C: &[u8] = &[3]; // TODO: check this to be sure it fits all types of CTRL_C (with mac, etc)
 const TERMINATING_STRING: &str = "\0";
 const DELETE_KEY: &str = "\u{007F}";
 const BACKSPACE_KEY: &str = "\u{0008}";
@@ -74,7 +78,7 @@ impl AnsiEncoding {
 
 #[derive(PartialEq, Eq, Ord, PartialOrd, Hash, Clone, Copy, Debug)]
 pub enum PaneId {
-    Terminal(RawFd),
+    Terminal(u32),
     Plugin(u32), // FIXME: Drop the trait object, make this a wrapper for the struct?
 }
 
@@ -83,7 +87,7 @@ pub enum PaneId {
 #[allow(clippy::too_many_arguments)]
 pub struct TerminalPane {
     pub grid: Grid,
-    pub pid: RawFd,
+    pub pid: u32,
     pub selectable: bool,
     pub geom: PaneGeom,
     pub geom_override: Option<PaneGeom>,
@@ -99,6 +103,8 @@ pub struct TerminalPane {
     borderless: bool,
     fake_cursor_locations: HashSet<(usize, usize)>, // (x, y) - these hold a record of previous fake cursors which we need to clear on render
     search_term: String,
+    is_held: Option<(Option<i32>, RunCommand)>, // a "held" pane means that its command has exited and its waiting for a
+                                                // possible user instruction to be re-run
 }
 
 impl Pane for TerminalPane {
@@ -157,53 +163,83 @@ impl Pane for TerminalPane {
             .cursor_coordinates()
             .map(|(x, y)| (x + left, y + top))
     }
-    fn adjust_input_to_terminal(&self, input_bytes: Vec<u8>) -> Vec<u8> {
+    fn adjust_input_to_terminal(&mut self, input_bytes: Vec<u8>) -> Option<AdjustedInput> {
         // there are some cases in which the terminal state means that input sent to it
         // needs to be adjusted.
         // here we match against those cases - if need be, we adjust the input and if not
         // we send back the original input
-        if self.grid.new_line_mode {
-            if let &[13] = input_bytes.as_slice() {
-                // LNM - carriage return is followed by linefeed
-                return "\u{0d}\u{0a}".as_bytes().to_vec();
-            };
-        }
-        if self.grid.cursor_key_mode {
+        if let Some((_exit_status, run_command)) = &self.is_held {
             match input_bytes.as_slice() {
-                LEFT_ARROW => {
-                    return AnsiEncoding::Left.as_vec_bytes();
+                ENTER_CARRIAGE_RETURN | ENTER_NEWLINE | SPACE => {
+                    let run_command = run_command.clone();
+                    self.is_held = None;
+                    self.grid.reset_terminal_state();
+                    self.set_should_render(true);
+                    Some(AdjustedInput::ReRunCommandInThisPane(run_command))
                 },
-                RIGHT_ARROW => {
-                    return AnsiEncoding::Right.as_vec_bytes();
-                },
-                UP_ARROW => {
-                    return AnsiEncoding::Up.as_vec_bytes();
-                },
-                DOWN_ARROW => {
-                    return AnsiEncoding::Down.as_vec_bytes();
-                },
-
-                HOME_KEY => {
-                    return AnsiEncoding::Home.as_vec_bytes();
-                },
-                END_KEY => {
-                    return AnsiEncoding::End.as_vec_bytes();
-                },
-                _ => {},
-            };
-        }
-
-        if !self.grid.bracketed_paste_mode {
-            // Zellij itself operates in bracketed paste mode, so the terminal sends these
-            // instructions (bracketed paste start and bracketed paste end respectively)
-            // when pasting input. We only need to make sure not to send them to terminal
-            // panes who do not work in this mode
-            match input_bytes.as_slice() {
-                BRACKETED_PASTE_BEGIN | BRACKETED_PASTE_END => return vec![],
-                _ => {},
+                CTRL_C => Some(AdjustedInput::CloseThisPane),
+                _ => None,
             }
+        } else {
+            if self.grid.new_line_mode {
+                if let &[13] = input_bytes.as_slice() {
+                    // LNM - carriage return is followed by linefeed
+                    return Some(AdjustedInput::WriteBytesToTerminal(
+                        "\u{0d}\u{0a}".as_bytes().to_vec(),
+                    ));
+                };
+            }
+            if self.grid.cursor_key_mode {
+                match input_bytes.as_slice() {
+                    LEFT_ARROW => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(
+                            AnsiEncoding::Left.as_vec_bytes(),
+                        ));
+                    },
+                    RIGHT_ARROW => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(
+                            AnsiEncoding::Right.as_vec_bytes(),
+                        ));
+                    },
+                    UP_ARROW => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(
+                            AnsiEncoding::Up.as_vec_bytes(),
+                        ));
+                    },
+                    DOWN_ARROW => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(
+                            AnsiEncoding::Down.as_vec_bytes(),
+                        ));
+                    },
+
+                    HOME_KEY => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(
+                            AnsiEncoding::Home.as_vec_bytes(),
+                        ));
+                    },
+                    END_KEY => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(
+                            AnsiEncoding::End.as_vec_bytes(),
+                        ));
+                    },
+                    _ => {},
+                };
+            }
+
+            if !self.grid.bracketed_paste_mode {
+                // Zellij itself operates in bracketed paste mode, so the terminal sends these
+                // instructions (bracketed paste start and bracketed paste end respectively)
+                // when pasting input. We only need to make sure not to send them to terminal
+                // panes who do not work in this mode
+                match input_bytes.as_slice() {
+                    BRACKETED_PASTE_BEGIN | BRACKETED_PASTE_END => {
+                        return Some(AdjustedInput::WriteBytesToTerminal(vec![]))
+                    },
+                    _ => {},
+                }
+            }
+            Some(AdjustedInput::WriteBytesToTerminal(input_bytes))
         }
-        input_bytes
     }
     fn position_and_size(&self) -> PaneGeom {
         self.geom
@@ -307,7 +343,9 @@ impl Pane for TerminalPane {
         input_mode: InputMode,
     ) -> Option<(Vec<CharacterChunk>, Option<String>)> {
         // TODO: remove the cursor stuff from here
-        let pane_title = if self.pane_name.is_empty()
+        let pane_title = if let Some((_exit_status, run_command)) = &self.is_held {
+            format!("{}", run_command)
+        } else if self.pane_name.is_empty()
             && input_mode == InputMode::RenamePane
             && frame_params.is_main_client
         {
@@ -346,12 +384,15 @@ impl Pane for TerminalPane {
             self.pane_name.clone()
         };
 
-        let frame = PaneFrame::new(
+        let mut frame = PaneFrame::new(
             self.current_geom().into(),
             self.grid.scrollback_position_and_length(),
             pane_title,
             frame_params,
         );
+        if let Some((exit_status, _run_command)) = &self.is_held {
+            frame.add_exit_status(exit_status.as_ref().copied());
+        }
 
         match self.frame.get(&client_id) {
             // TODO: use and_then or something?
@@ -654,12 +695,16 @@ impl Pane for TerminalPane {
     fn is_alternate_mode_active(&self) -> bool {
         self.grid.is_alternate_mode_active()
     }
+    fn hold(&mut self, exit_status: Option<i32>, run_command: RunCommand) {
+        self.is_held = Some((exit_status, run_command));
+        self.set_should_render(true);
+    }
 }
 
 impl TerminalPane {
     #[allow(clippy::too_many_arguments)]
     pub fn new(
-        pid: RawFd,
+        pid: u32,
         position_and_size: PaneGeom,
         style: Style,
         pane_index: usize,
@@ -669,8 +714,10 @@ impl TerminalPane {
         sixel_image_store: Rc<RefCell<SixelImageStore>>,
         terminal_emulator_colors: Rc<RefCell<Palette>>,
         terminal_emulator_color_codes: Rc<RefCell<HashMap<usize, String>>>,
+        initial_pane_title: Option<String>,
     ) -> TerminalPane {
-        let initial_pane_title = format!("Pane #{}", pane_index);
+        let initial_pane_title =
+            initial_pane_title.unwrap_or_else(|| format!("Pane #{}", pane_index));
         let grid = Grid::new(
             position_and_size.rows.as_usize(),
             position_and_size.cols.as_usize(),
@@ -698,6 +745,7 @@ impl TerminalPane {
             borderless: false,
             fake_cursor_locations: HashSet::new(),
             search_term: String::new(),
+            is_held: None,
         }
     }
     pub fn get_x(&self) -> usize {

zellij-server/src/panes/tiled_panes/mod.rs

@@ -14,6 +14,7 @@ use std::rc::Rc;
 use std::time::Instant;
 use zellij_utils::{
     data::{ModeInfo, Style},
+    input::command::RunCommand,
     input::layout::SplitDirection,
     pane_size::{Offset, PaneGeom, Size, SizeInPixels, Viewport},
 };
@@ -21,9 +22,9 @@ use zellij_utils::{
 macro_rules! resize_pty {
     ($pane:expr, $os_input:expr) => {
         if let PaneId::Terminal(ref pid) = $pane.pid() {
-            // FIXME: This `set_terminal_size_using_fd` call would be best in
+            // FIXME: This `set_terminal_size_using_terminal_id` call would be best in
             // `TerminalPane::reflow_lines`
-            $os_input.set_terminal_size_using_fd(
+            $os_input.set_terminal_size_using_terminal_id(
                 *pid,
                 $pane.get_content_columns() as u16,
                 $pane.get_content_rows() as u16,
@@ -993,6 +994,16 @@ impl TiledPanes {
             None
         }
     }
+    pub fn hold_pane(
+        &mut self,
+        pane_id: PaneId,
+        exit_status: Option<i32>,
+        run_command: RunCommand,
+    ) {
+        self.panes
+            .get_mut(&pane_id)
+            .map(|p| p.hold(exit_status, run_command));
+    }
     pub fn panes_to_hide_contains(&self, pane_id: PaneId) -> bool {
         self.panes_to_hide.contains(&pane_id)
     }

zellij-server/src/panes/unit/search_in_pane_tests.rs

@@ -39,6 +39,7 @@ fn create_pane() -> TerminalPane {
         sixel_image_store,
         Rc::new(RefCell::new(Palette::default())),
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let content = read_fixture();
     terminal_pane.handle_pty_bytes(content);

zellij-server/src/panes/unit/terminal_pane_tests.rs

@@ -47,6 +47,7 @@ pub fn scrolling_inside_a_pane() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let mut text_to_fill_pane = String::new();
     for i in 0..30 {
@@ -87,6 +88,7 @@ pub fn sixel_image_inside_terminal_pane() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let sixel_image_bytes = "\u{1b}Pq
         #0;2;0;0;0#1;2;100;100;0#2;2;0;100;0
@@ -127,6 +129,7 @@ pub fn partial_sixel_image_inside_terminal_pane() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let pane_content = read_fixture("sixel-image-500px.six");
     terminal_pane.handle_pty_bytes(pane_content);
@@ -161,6 +164,7 @@ pub fn overflowing_sixel_image_inside_terminal_pane() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let pane_content = read_fixture("sixel-image-500px.six");
     terminal_pane.handle_pty_bytes(pane_content);
@@ -194,6 +198,7 @@ pub fn scrolling_through_a_sixel_image() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let mut text_to_fill_pane = String::new();
     for i in 0..30 {
@@ -238,6 +243,7 @@ pub fn multiple_sixel_images_in_pane() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let mut text_to_fill_pane = String::new();
     for i in 0..5 {
@@ -280,6 +286,7 @@ pub fn resizing_pane_with_sixel_images() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let mut text_to_fill_pane = String::new();
     for i in 0..5 {
@@ -325,6 +332,7 @@ pub fn changing_character_cell_size_with_sixel_images() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
     let mut text_to_fill_pane = String::new();
     for i in 0..5 {
@@ -375,6 +383,7 @@ pub fn keep_working_after_corrupted_sixel_image() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
 
     let sixel_image_bytes = "\u{1b}PI AM CORRUPTED BWAHAHAq
@@ -423,6 +432,7 @@ pub fn pane_with_frame_position_is_on_frame() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
 
     terminal_pane.set_content_offset(Offset::frame(1));
@@ -507,6 +517,7 @@ pub fn pane_with_bottom_and_right_borders_position_is_on_frame() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
 
     terminal_pane.set_content_offset(Offset::shift(1, 1));
@@ -591,6 +602,7 @@ pub fn frameless_pane_position_is_on_frame() {
         sixel_image_store,
         terminal_emulator_colors,
         terminal_emulator_color_codes,
+        None,
     ); // 0 is the pane index
 
     terminal_pane.set_content_offset(Offset::default());

zellij-server/src/pty.rs

@@ -1,6 +1,10 @@
+use crate::os_input_output::SpawnTerminalError;
 use crate::terminal_bytes::TerminalBytes;
 use crate::{
-    panes::PaneId, screen::ScreenInstruction, thread_bus::Bus, wasm_vm::PluginInstruction,
+    panes::PaneId,
+    screen::ScreenInstruction,
+    thread_bus::{Bus, ThreadSenders},
+    wasm_vm::PluginInstruction,
     ClientId, ServerInstruction,
 };
 use async_std::task::{self, JoinHandle};
@@ -27,7 +31,8 @@ pub enum ClientOrTabIndex {
 /// Instructions related to PTYs (pseudoterminals).
 #[derive(Clone, Debug)]
 pub(crate) enum PtyInstruction {
-    SpawnTerminal(Option<TerminalAction>, ClientOrTabIndex),
+    SpawnTerminal(Option<TerminalAction>, Option<bool>, ClientOrTabIndex), // bool (if Some) is
+    // should_float
     OpenInPlaceEditor(PathBuf, Option<usize>, ClientId), // Option<usize> is the optional line number
     SpawnTerminalVertically(Option<TerminalAction>, ClientId),
     SpawnTerminalHorizontally(Option<TerminalAction>, ClientId),
@@ -41,6 +46,7 @@ pub(crate) enum PtyInstruction {
     ), // the String is the tab name
     ClosePane(PaneId),
     CloseTab(Vec<PaneId>),
+    ReRunCommandInPane(PaneId, RunCommand),
     Exit,
 }
 
@@ -56,6 +62,7 @@ impl From<&PtyInstruction> for PtyContext {
             PtyInstruction::ClosePane(_) => PtyContext::ClosePane,
             PtyInstruction::CloseTab(_) => PtyContext::CloseTab,
             PtyInstruction::NewTab(..) => PtyContext::NewTab,
+            PtyInstruction::ReRunCommandInPane(..) => PtyContext::ReRunCommandInPane,
             PtyInstruction::Exit => PtyContext::Exit,
         }
     }
@@ -64,9 +71,9 @@ impl From<&PtyInstruction> for PtyContext {
 pub(crate) struct Pty {
     pub active_panes: HashMap<ClientId, PaneId>,
     pub bus: Bus<PtyInstruction>,
-    pub id_to_child_pid: HashMap<RawFd, RawFd>, // pty_primary => child raw fd
+    pub id_to_child_pid: HashMap<u32, RawFd>, // terminal_id => child raw fd
     debug_to_file: bool,
-    task_handles: HashMap<RawFd, JoinHandle<()>>,
+    task_handles: HashMap<u32, JoinHandle<()>>, // terminal_id to join-handle
     default_editor: Option<PathBuf>,
 }
 
@@ -75,17 +82,53 @@ pub(crate) fn pty_thread_main(mut pty: Pty, layout: Box<Layout>) {
         let (event, mut err_ctx) = pty.bus.recv().expect("failed to receive event on channel");
         err_ctx.add_call(ContextType::Pty((&event).into()));
         match event {
-            PtyInstruction::SpawnTerminal(terminal_action, client_or_tab_index) => {
-                let pid = pty
-                    .spawn_terminal(terminal_action, client_or_tab_index)
-                    .unwrap(); // TODO: handle error here
-                pty.bus
-                    .senders
-                    .send_to_screen(ScreenInstruction::NewPane(
-                        PaneId::Terminal(pid),
-                        client_or_tab_index,
-                    ))
-                    .unwrap();
+            PtyInstruction::SpawnTerminal(terminal_action, should_float, client_or_tab_index) => {
+                let (hold_on_close, run_command, pane_title) = match &terminal_action {
+                    Some(TerminalAction::RunCommand(run_command)) => (
+                        run_command.hold_on_close,
+                        Some(run_command.clone()),
+                        Some(run_command.to_string()),
+                    ),
+                    _ => (false, None, None),
+                };
+                match pty.spawn_terminal(terminal_action, client_or_tab_index) {
+                    Ok(pid) => {
+                        pty.bus
+                            .senders
+                            .send_to_screen(ScreenInstruction::NewPane(
+                                PaneId::Terminal(pid),
+                                pane_title,
+                                should_float,
+                                client_or_tab_index,
+                            ))
+                            .unwrap();
+                    },
+                    Err(SpawnTerminalError::CommandNotFound(pid)) => {
+                        if hold_on_close {
+                            pty.bus
+                                .senders
+                                .send_to_screen(ScreenInstruction::NewPane(
+                                    PaneId::Terminal(pid),
+                                    pane_title,
+                                    should_float,
+                                    client_or_tab_index,
+                                ))
+                                .unwrap();
+                            if let Some(run_command) = run_command {
+                                send_command_not_found_to_screen(
+                                    pty.bus.senders.clone(),
+                                    pid,
+                                    run_command.clone(),
+                                );
+                            }
+                        } else {
+                            pty.close_pane(PaneId::Terminal(pid));
+                        }
+                    },
+                    Err(e) => {
+                        log::error!("Failed to spawn terminal: {}", e);
+                    },
+                }
             },
             PtyInstruction::OpenInPlaceEditor(temp_file, line_number, client_id) => {
                 match pty.spawn_terminal(
@@ -107,28 +150,124 @@ pub(crate) fn pty_thread_main(mut pty: Pty, layout: Box<Layout>) {
                 }
             },
             PtyInstruction::SpawnTerminalVertically(terminal_action, client_id) => {
-                let pid = pty
-                    .spawn_terminal(terminal_action, ClientOrTabIndex::ClientId(client_id))
-                    .unwrap(); // TODO: handle error here
-                pty.bus
-                    .senders
-                    .send_to_screen(ScreenInstruction::VerticalSplit(
-                        PaneId::Terminal(pid),
-                        client_id,
-                    ))
-                    .unwrap();
+                let (hold_on_close, run_command, pane_title) = match &terminal_action {
+                    Some(TerminalAction::RunCommand(run_command)) => (
+                        run_command.hold_on_close,
+                        Some(run_command.clone()),
+                        Some(run_command.to_string()),
+                    ),
+                    _ => (false, None, None),
+                };
+                match pty.spawn_terminal(terminal_action, ClientOrTabIndex::ClientId(client_id)) {
+                    Ok(pid) => {
+                        pty.bus
+                            .senders
+                            .send_to_screen(ScreenInstruction::VerticalSplit(
+                                PaneId::Terminal(pid),
+                                pane_title,
+                                client_id,
+                            ))
+                            .unwrap();
+                    },
+                    Err(SpawnTerminalError::CommandNotFound(pid)) => {
+                        if hold_on_close {
+                            pty.bus
+                                .senders
+                                .send_to_screen(ScreenInstruction::VerticalSplit(
+                                    PaneId::Terminal(pid),
+                                    pane_title,
+                                    client_id,
+                                ))
+                                .unwrap();
+                            if let Some(run_command) = run_command {
+                                pty.bus
+                                    .senders
+                                    .send_to_screen(ScreenInstruction::PtyBytes(
+                                        pid,
+                                        format!(
+                                            "Command not found: {}",
+                                            run_command.command.display()
+                                        )
+                                        .as_bytes()
+                                        .to_vec(),
+                                    ))
+                                    .unwrap();
+                                pty.bus
+                                    .senders
+                                    .send_to_screen(ScreenInstruction::HoldPane(
+                                        PaneId::Terminal(pid),
+                                        Some(2), // exit status
+                                        run_command,
+                                        None,
+                                    ))
+                                    .unwrap();
+                            }
+                        }
+                    },
+                    Err(e) => {
+                        log::error!("Failed to spawn terminal: {}", e);
+                    },
+                }
             },
             PtyInstruction::SpawnTerminalHorizontally(terminal_action, client_id) => {
-                let pid = pty
-                    .spawn_terminal(terminal_action, ClientOrTabIndex::ClientId(client_id))
-                    .unwrap(); // TODO: handle error here
-                pty.bus
-                    .senders
-                    .send_to_screen(ScreenInstruction::HorizontalSplit(
-                        PaneId::Terminal(pid),
-                        client_id,
-                    ))
-                    .unwrap();
+                let (hold_on_close, run_command, pane_title) = match &terminal_action {
+                    Some(TerminalAction::RunCommand(run_command)) => (
+                        run_command.hold_on_close,
+                        Some(run_command.clone()),
+                        Some(run_command.to_string()),
+                    ),
+                    _ => (false, None, None),
+                };
+                match pty.spawn_terminal(terminal_action, ClientOrTabIndex::ClientId(client_id)) {
+                    Ok(pid) => {
+                        pty.bus
+                            .senders
+                            .send_to_screen(ScreenInstruction::HorizontalSplit(
+                                PaneId::Terminal(pid),
+                                pane_title,
+                                client_id,
+                            ))
+                            .unwrap();
+                    },
+                    Err(SpawnTerminalError::CommandNotFound(pid)) => {
+                        if hold_on_close {
+                            pty.bus
+                                .senders
+                                .send_to_screen(ScreenInstruction::HorizontalSplit(
+                                    PaneId::Terminal(pid),
+                                    pane_title,
+                                    client_id,
+                                ))
+                                .unwrap();
+                            if let Some(run_command) = run_command {
+                                pty.bus
+                                    .senders
+                                    .send_to_screen(ScreenInstruction::PtyBytes(
+                                        pid,
+                                        format!(
+                                            "Command not found: {}",
+                                            run_command.command.display()
+                                        )
+                                        .as_bytes()
+                                        .to_vec(),
+                                    ))
+                                    .unwrap();
+                                pty.bus
+                                    .senders
+                                    .send_to_screen(ScreenInstruction::HoldPane(
+                                        PaneId::Terminal(pid),
+                                        Some(2), // exit status
+                                        run_command,
+                                        None,
+                                    ))
+                                    .unwrap();
+                            }
+                        }
+                    },
+                    Err(e) => {
+                        log::error!("Failed to spawn terminal: {}", e);
+                    },
+                }
             },
             PtyInstruction::UpdateActivePane(pane_id, client_id) => {
                 pty.set_active_pane(pane_id, client_id);
@@ -175,6 +314,36 @@ pub(crate) fn pty_thread_main(mut pty: Pty, layout: Box<Layout>) {
                     .send_to_server(ServerInstruction::UnblockInputThread)
                     .unwrap();
             },
+            PtyInstruction::ReRunCommandInPane(pane_id, run_command) => {
+                match pty.rerun_command_in_pane(pane_id, run_command.clone()) {
+                    Ok(..) => {},
+                    Err(SpawnTerminalError::CommandNotFound(pid)) => {
+                        if run_command.hold_on_close {
+                            pty.bus
+                                .senders
+                                .send_to_screen(ScreenInstruction::PtyBytes(
+                                    pid,
+                                    format!("Command not found: {}", run_command.command.display())
+                                        .as_bytes()
+                                        .to_vec(),
+                                ))
+                                .unwrap();
+                            pty.bus
+                                .senders
+                                .send_to_screen(ScreenInstruction::HoldPane(
+                                    PaneId::Terminal(pid),
+                                    Some(2), // exit status
+                                    run_command,
+                                    None,
+                                ))
+                                .unwrap();
+                        }
+                    },
+                    Err(e) => {
+                        log::error!("Failed to spawn terminal: {}", e);
+                    },
+                }
+            },
             PtyInstruction::Exit => break,
         }
     }
@@ -200,6 +369,7 @@ impl Pty {
             args: vec![],
             command: PathBuf::from(env::var("SHELL").expect("Could not find the SHELL variable")),
             cwd: None, // this should be filled by the calling function, eg. spawn_terminal
+            hold_on_close: false,
         })
     }
     fn fill_cwd(&self, terminal_action: &mut TerminalAction, client_id: ClientId) {
@@ -225,7 +395,8 @@ impl Pty {
         &mut self,
         terminal_action: Option<TerminalAction>,
         client_or_tab_index: ClientOrTabIndex,
-    ) -> Result<RawFd, &'static str> {
+    ) -> Result<u32, SpawnTerminalError> {
+        // returns the terminal id
         let terminal_action = match client_or_tab_index {
             ClientOrTabIndex::ClientId(client_id) => {
                 let mut terminal_action =
@@ -237,13 +408,26 @@ impl Pty {
                 terminal_action.unwrap_or_else(|| self.get_default_terminal())
             },
         };
+        let hold_on_close = match &terminal_action {
+            TerminalAction::RunCommand(run_command) => run_command.hold_on_close,
+            _ => false,
+        };
         let quit_cb = Box::new({
             let senders = self.bus.senders.clone();
-            move |pane_id| {
-                let _ = senders.send_to_screen(ScreenInstruction::ClosePane(pane_id, None));
+            move |pane_id, exit_status, command| {
+                if hold_on_close {
+                    let _ = senders.send_to_screen(ScreenInstruction::HoldPane(
+                        pane_id,
+                        exit_status,
+                        command,
+                        None,
+                    ));
+                } else {
+                    let _ = senders.send_to_screen(ScreenInstruction::ClosePane(pane_id, None));
+                }
             }
         });
-        let (pid_primary, child_fd): (RawFd, RawFd) = self
+        let (terminal_id, pid_primary, child_fd): (u32, RawFd, RawFd) = self
             .bus
             .os_input
             .as_mut()
@@ -254,15 +438,15 @@ impl Pty {
             let os_input = self.bus.os_input.as_ref().unwrap().clone();
             let debug_to_file = self.debug_to_file;
             async move {
-                TerminalBytes::new(pid_primary, senders, os_input, debug_to_file)
+                TerminalBytes::new(pid_primary, senders, os_input, debug_to_file, terminal_id)
                     .listen()
                     .await;
             }
         });
 
-        self.task_handles.insert(pid_primary, terminal_bytes);
-        self.id_to_child_pid.insert(pid_primary, child_fd);
-        Ok(pid_primary)
+        self.task_handles.insert(terminal_id, terminal_bytes);
+        self.id_to_child_pid.insert(terminal_id, child_fd);
+        Ok(terminal_id)
     }
     pub fn spawn_terminals_for_layout(
         &mut self,
@@ -273,77 +457,155 @@ impl Pty {
         let mut default_shell = default_shell.unwrap_or_else(|| self.get_default_terminal());
         self.fill_cwd(&mut default_shell, client_id);
         let extracted_run_instructions = layout.extract_run_instructions();
-        let mut new_pane_pids = vec![];
+        let mut new_pane_pids: Vec<(u32, Option<RunCommand>, Result<RawFd, SpawnTerminalError>)> =
+            vec![]; // (terminal_id,
+                    // run_command
+                    // file_descriptor)
         for run_instruction in extracted_run_instructions {
             let quit_cb = Box::new({
                 let senders = self.bus.senders.clone();
-                move |pane_id| {
+                move |pane_id, _exit_status, _command| {
                     let _ = senders.send_to_screen(ScreenInstruction::ClosePane(pane_id, None));
                 }
             });
             match run_instruction {
                 Some(Run::Command(command)) => {
-                    let cmd = TerminalAction::RunCommand(command);
-                    let (pid_primary, child_fd): (RawFd, RawFd) = self
-                        .bus
-                        .os_input
-                        .as_mut()
-                        .unwrap()
-                        .spawn_terminal(cmd, quit_cb, self.default_editor.clone())
-                        .unwrap(); // TODO: handle error here
-                    self.id_to_child_pid.insert(pid_primary, child_fd);
-                    new_pane_pids.push(pid_primary);
+                    let hold_on_close = command.hold_on_close;
+                    let quit_cb = Box::new({
+                        let senders = self.bus.senders.clone();
+                        move |pane_id, exit_status, command| {
+                            if hold_on_close {
+                                let _ = senders.send_to_screen(ScreenInstruction::HoldPane(
+                                    pane_id,
+                                    exit_status,
+                                    command,
+                                    None,
+                                ));
+                            } else {
+                                let _ = senders
+                                    .send_to_screen(ScreenInstruction::ClosePane(pane_id, None));
+                            }
+                        }
+                    });
+                    let cmd = TerminalAction::RunCommand(command.clone());
+                    match self.bus.os_input.as_mut().unwrap().spawn_terminal(
+                        cmd,
+                        quit_cb,
+                        self.default_editor.clone(),
+                    ) {
+                        Ok((terminal_id, pid_primary, child_fd)) => {
+                            self.id_to_child_pid.insert(terminal_id, child_fd);
+                            new_pane_pids.push((
+                                terminal_id,
+                                Some(command.clone()),
+                                Ok(pid_primary),
+                            ));
+                        },
+                        Err(SpawnTerminalError::CommandNotFound(terminal_id)) => {
+                            new_pane_pids.push((
+                                terminal_id,
+                                Some(command.clone()),
+                                Err(SpawnTerminalError::CommandNotFound(terminal_id)),
+                            ));
+                        },
+                        Err(e) => {
+                            log::error!("Failed to spawn terminal: {}", e);
+                        },
+                    }
                 },
                 None => {
-                    let (pid_primary, child_fd): (RawFd, RawFd) = self
-                        .bus
-                        .os_input
-                        .as_mut()
-                        .unwrap()
-                        .spawn_terminal(default_shell.clone(), quit_cb, self.default_editor.clone())
-                        .unwrap(); // TODO: handle error here
-                    self.id_to_child_pid.insert(pid_primary, child_fd);
-                    new_pane_pids.push(pid_primary);
+                    match self.bus.os_input.as_mut().unwrap().spawn_terminal(
+                        default_shell.clone(),
+                        quit_cb,
+                        self.default_editor.clone(),
+                    ) {
+                        Ok((terminal_id, pid_primary, child_fd)) => {
+                            self.id_to_child_pid.insert(terminal_id, child_fd);
+                            new_pane_pids.push((terminal_id, None, Ok(pid_primary)));
+                        },
+                        Err(SpawnTerminalError::CommandNotFound(terminal_id)) => {
+                            new_pane_pids.push((
+                                terminal_id,
+                                None,
+                                Err(SpawnTerminalError::CommandNotFound(terminal_id)),
+                            ));
+                        },
+                        Err(e) => {
+                            log::error!("Failed to spawn terminal: {}", e);
+                        },
+                    }
                 },
                 // Investigate moving plugin loading to here.
                 Some(Run::Plugin(_)) => {},
             }
         }
+        let new_tab_pane_ids: Vec<u32> = new_pane_pids
+            .iter()
+            .map(|(terminal_id, _, _)| *terminal_id)
+            .collect::<Vec<u32>>();
         self.bus
             .senders
             .send_to_screen(ScreenInstruction::NewTab(
                 layout,
-                new_pane_pids.clone(),
+                new_tab_pane_ids,
                 client_id,
             ))
             .unwrap();
-        for id in new_pane_pids {
-            let terminal_bytes = task::spawn({
-                let senders = self.bus.senders.clone();
-                let os_input = self.bus.os_input.as_ref().unwrap().clone();
-                let debug_to_file = self.debug_to_file;
-                async move {
-                    TerminalBytes::new(id, senders, os_input, debug_to_file)
-                        .listen()
-                        .await;
-                }
-            });
-            self.task_handles.insert(id, terminal_bytes);
+        for (terminal_id, run_command, pid_primary) in new_pane_pids {
+            match pid_primary {
+                Ok(pid_primary) => {
+                    let terminal_bytes = task::spawn({
+                        let senders = self.bus.senders.clone();
+                        let os_input = self.bus.os_input.as_ref().unwrap().clone();
+                        let debug_to_file = self.debug_to_file;
+                        async move {
+                            TerminalBytes::new(
+                                pid_primary,
+                                senders,
+                                os_input,
+                                debug_to_file,
+                                terminal_id,
+                            )
+                            .listen()
+                            .await;
+                        }
+                    });
+                    self.task_handles.insert(terminal_id, terminal_bytes);
+                },
+                _ => match run_command {
+                    Some(run_command) => {
+                        if run_command.hold_on_close {
+                            send_command_not_found_to_screen(
+                                self.bus.senders.clone(),
+                                terminal_id,
+                                run_command.clone(),
+                            );
+                        } else {
+                            self.close_pane(PaneId::Terminal(terminal_id));
+                        }
+                    },
+                    None => {
+                        self.close_pane(PaneId::Terminal(terminal_id));
+                    },
+                },
+            }
         }
     }
     pub fn close_pane(&mut self, id: PaneId) {
         match id {
             PaneId::Terminal(id) => {
-                let child_fd = self.id_to_child_pid.remove(&id).unwrap();
-                self.task_handles.remove(&id).unwrap();
-                task::block_on(async {
-                    self.bus
-                        .os_input
-                        .as_mut()
-                        .unwrap()
-                        .kill(Pid::from_raw(child_fd))
-                        .unwrap();
-                });
+                self.task_handles.remove(&id);
+                if let Some(child_fd) = self.id_to_child_pid.remove(&id) {
+                    task::block_on(async {
+                        self.bus
+                            .os_input
+                            .as_mut()
+                            .unwrap()
+                            .kill(Pid::from_raw(child_fd))
+                            .unwrap();
+                    });
+                }
+                self.bus.os_input.as_ref().unwrap().clear_terminal_id(id);
             },
             PaneId::Plugin(pid) => drop(
                 self.bus
@@ -362,13 +624,84 @@ impl Pty {
             self.active_panes.insert(client_id, pane_id);
         }
     }
+    pub fn rerun_command_in_pane(
+        &mut self,
+        pane_id: PaneId,
+        run_command: RunCommand,
+    ) -> Result<(), SpawnTerminalError> {
+        match pane_id {
+            PaneId::Terminal(id) => {
+                let _ = self.task_handles.remove(&id); // if all is well, this shouldn't be here
+                let _ = self.id_to_child_pid.remove(&id); // if all is wlel, this shouldn't be here
+
+                let quit_cb = Box::new({
+                    let senders = self.bus.senders.clone();
+                    move |pane_id, exit_status, command| {
+                        // we only re-run held panes, so we'll never close them from Pty
+                        let _ = senders.send_to_screen(ScreenInstruction::HoldPane(
+                            pane_id,
+                            exit_status,
+                            command,
+                            None,
+                        ));
+                    }
+                });
+                let (pid_primary, child_fd): (RawFd, RawFd) =
+                    self.bus
+                        .os_input
+                        .as_mut()
+                        .unwrap()
+                        .re_run_command_in_terminal(id, run_command, quit_cb)?;
+                let terminal_bytes = task::spawn({
+                    let senders = self.bus.senders.clone();
+                    let os_input = self.bus.os_input.as_ref().unwrap().clone();
+                    let debug_to_file = self.debug_to_file;
+                    async move {
+                        TerminalBytes::new(pid_primary, senders, os_input, debug_to_file, id)
+                            .listen()
+                            .await;
+                    }
+                });
+
+                self.task_handles.insert(id, terminal_bytes);
+                self.id_to_child_pid.insert(id, child_fd);
+                Ok(())
+            },
+            _ => Err(SpawnTerminalError::GenericSpawnError(
+                "Cannot respawn plugin panes",
+            )),
+        }
+    }
 }
 
 impl Drop for Pty {
     fn drop(&mut self) {
-        let child_ids: Vec<RawFd> = self.id_to_child_pid.keys().copied().collect();
+        let child_ids: Vec<u32> = self.id_to_child_pid.keys().copied().collect();
         for id in child_ids {
             self.close_pane(PaneId::Terminal(id));
         }
     }
 }
+
+fn send_command_not_found_to_screen(
+    senders: ThreadSenders,
+    terminal_id: u32,
+    run_command: RunCommand,
+) {
+    senders
+        .send_to_screen(ScreenInstruction::PtyBytes(
+            terminal_id,
+            format!("Command not found: {}", run_command.command.display())
+                .as_bytes()
+                .to_vec(),
+        ))
+        .unwrap();
+    senders
+        .send_to_screen(ScreenInstruction::HoldPane(
+            PaneId::Terminal(terminal_id),
+            Some(2),
+            run_command.clone(),
+            None,
+        ))
+        .unwrap();
+}

zellij-server/src/pty_writer.rs

@@ -4,7 +4,7 @@ use crate::thread_bus::Bus;
 
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub(crate) enum PtyWriteInstruction {
-    Write(Vec<u8>, i32),
+    Write(Vec<u8>, u32),
     Exit,
 }
 

zellij-server/src/route.rs

@@ -245,29 +245,17 @@ pub(crate) fn route_action(
                     PtyInstruction::SpawnTerminalHorizontally(shell, client_id)
                 },
                 // No direction specified - try to put it in the biggest available spot
-                None => PtyInstruction::SpawnTerminal(shell, ClientOrTabIndex::ClientId(client_id)),
+                None => PtyInstruction::SpawnTerminal(
+                    shell,
+                    None,
+                    ClientOrTabIndex::ClientId(client_id),
+                ),
             };
             session.senders.send_to_pty(pty_instr).unwrap();
         },
         Action::EditFile(path_to_file, line_number, split_direction, should_float) => {
-            match should_float {
-                Some(true) => {
-                    session
-                        .senders
-                        .send_to_screen(ScreenInstruction::ShowFloatingPanes(client_id))
-                        .unwrap();
-                },
-                Some(false) => {
-                    session
-                        .senders
-                        .send_to_screen(ScreenInstruction::HideFloatingPanes(client_id))
-                        .unwrap();
-                },
-                None => {},
-            };
-
             let open_file = TerminalAction::OpenFile(path_to_file, line_number);
-            let pty_instr = match (split_direction, should_float.unwrap_or(false)) {
+            let pty_instr = match (split_direction, should_float) {
                 (Some(Direction::Left), false) => {
                     PtyInstruction::SpawnTerminalVertically(Some(open_file), client_id)
                 },
@@ -283,6 +271,7 @@ pub(crate) fn route_action(
                 // No direction specified or should float - defer placement to screen
                 (None, _) | (_, true) => PtyInstruction::SpawnTerminal(
                     Some(open_file),
+                    Some(should_float),
                     ClientOrTabIndex::ClientId(client_id),
                 ),
             };
@@ -308,10 +297,7 @@ pub(crate) fn route_action(
                 .unwrap();
         },
         Action::NewFloatingPane(run_command) => {
-            session
-                .senders
-                .send_to_screen(ScreenInstruction::ShowFloatingPanes(client_id))
-                .unwrap();
+            let should_float = true;
             let run_cmd = run_command
                 .map(|cmd| TerminalAction::RunCommand(cmd.into()))
                 .or_else(|| session.default_shell.clone());
@@ -319,15 +305,13 @@ pub(crate) fn route_action(
                 .senders
                 .send_to_pty(PtyInstruction::SpawnTerminal(
                     run_cmd,
+                    Some(should_float),
                     ClientOrTabIndex::ClientId(client_id),
                 ))
                 .unwrap();
         },
         Action::NewTiledPane(direction, run_command) => {
-            session
-                .senders
-                .send_to_screen(ScreenInstruction::HideFloatingPanes(client_id))
-                .unwrap();
+            let should_float = false;
             let run_cmd = run_command
                 .map(|cmd| TerminalAction::RunCommand(cmd.into()))
                 .or_else(|| session.default_shell.clone());
@@ -345,9 +329,11 @@ pub(crate) fn route_action(
                     PtyInstruction::SpawnTerminalHorizontally(run_cmd, client_id)
                 },
                 // No direction specified - try to put it in the biggest available spot
-                None => {
-                    PtyInstruction::SpawnTerminal(run_cmd, ClientOrTabIndex::ClientId(client_id))
-                },
+                None => PtyInstruction::SpawnTerminal(
+                    run_cmd,
+                    Some(should_float),
+                    ClientOrTabIndex::ClientId(client_id),
+                ),
             };
             session.senders.send_to_pty(pty_instr).unwrap();
         },
@@ -394,9 +380,11 @@ pub(crate) fn route_action(
                     PtyInstruction::SpawnTerminalHorizontally(run_cmd, client_id)
                 },
                 // No direction specified - try to put it in the biggest available spot
-                None => {
-                    PtyInstruction::SpawnTerminal(run_cmd, ClientOrTabIndex::ClientId(client_id))
-                },
+                None => PtyInstruction::SpawnTerminal(
+                    run_cmd,
+                    None,
+                    ClientOrTabIndex::ClientId(client_id),
+                ),
             };
             session.senders.send_to_pty(pty_instr).unwrap();
         },

zellij-server/src/screen.rs

@@ -2,11 +2,11 @@
 
 use std::cell::RefCell;
 use std::collections::{BTreeMap, HashMap, HashSet};
-use std::os::unix::io::RawFd;
 use std::rc::Rc;
 use std::str;
 
 use zellij_utils::errors::prelude::*;
+use zellij_utils::input::command::RunCommand;
 use zellij_utils::input::options::Clipboard;
 use zellij_utils::pane_size::{Size, SizeInPixels};
 use zellij_utils::{input::command::TerminalAction, input::layout::PaneLayout, position::Position};
@@ -115,16 +115,16 @@ macro_rules! active_tab_and_connected_client_id {
 /// Instructions that can be sent to the [`Screen`].
 #[derive(Debug, Clone)]
 pub enum ScreenInstruction {
-    PtyBytes(RawFd, VteBytes),
+    PtyBytes(u32, VteBytes),
     Render,
-    NewPane(PaneId, ClientOrTabIndex),
+    NewPane(PaneId, Option<String>, Option<bool>, ClientOrTabIndex), // String is initial title,
+    // bool (if Some) is
+    // should_float
     OpenInPlaceEditor(PaneId, ClientId),
     TogglePaneEmbedOrFloating(ClientId),
     ToggleFloatingPanes(ClientId, Option<TerminalAction>),
-    ShowFloatingPanes(ClientId),
-    HideFloatingPanes(ClientId),
-    HorizontalSplit(PaneId, ClientId),
-    VerticalSplit(PaneId, ClientId),
+    HorizontalSplit(PaneId, Option<String>, ClientId), // String is initial title
+    VerticalSplit(PaneId, Option<String>, ClientId),   // String is initial title
     WriteCharacter(Vec<u8>, ClientId),
     ResizeLeft(ClientId),
     ResizeRight(ClientId),
@@ -164,9 +164,10 @@ pub enum ScreenInstruction {
     TogglePaneFrames,
     SetSelectable(PaneId, bool, usize),
     ClosePane(PaneId, Option<ClientId>),
+    HoldPane(PaneId, Option<i32>, RunCommand, Option<ClientId>), // Option<i32> is the exit status
     UpdatePaneName(Vec<u8>, ClientId),
     UndoRenamePane(ClientId),
-    NewTab(PaneLayout, Vec<RawFd>, ClientId),
+    NewTab(PaneLayout, Vec<u32>, ClientId),
     SwitchTabNext(ClientId),
     SwitchTabPrev(ClientId),
     ToggleActiveSyncTab(ClientId),
@@ -217,8 +218,6 @@ impl From<&ScreenInstruction> for ScreenContext {
                 ScreenContext::TogglePaneEmbedOrFloating
             },
             ScreenInstruction::ToggleFloatingPanes(..) => ScreenContext::ToggleFloatingPanes,
-            ScreenInstruction::ShowFloatingPanes(..) => ScreenContext::ShowFloatingPanes,
-            ScreenInstruction::HideFloatingPanes(..) => ScreenContext::HideFloatingPanes,
             ScreenInstruction::HorizontalSplit(..) => ScreenContext::HorizontalSplit,
             ScreenInstruction::VerticalSplit(..) => ScreenContext::VerticalSplit,
             ScreenInstruction::WriteCharacter(..) => ScreenContext::WriteCharacter,
@@ -264,6 +263,7 @@ impl From<&ScreenInstruction> for ScreenContext {
             ScreenInstruction::TogglePaneFrames => ScreenContext::TogglePaneFrames,
             ScreenInstruction::SetSelectable(..) => ScreenContext::SetSelectable,
             ScreenInstruction::ClosePane(..) => ScreenContext::ClosePane,
+            ScreenInstruction::HoldPane(..) => ScreenContext::HoldPane,
             ScreenInstruction::UpdatePaneName(..) => ScreenContext::UpdatePaneName,
             ScreenInstruction::UndoRenamePane(..) => ScreenContext::UndoRenamePane,
             ScreenInstruction::NewTab(..) => ScreenContext::NewTab,
@@ -811,7 +811,7 @@ impl Screen {
     pub fn new_tab(
         &mut self,
         layout: PaneLayout,
-        new_pids: Vec<RawFd>,
+        new_ids: Vec<u32>,
         client_id: ClientId,
     ) -> Result<()> {
         let client_id = if self.get_active_tab(client_id).is_some() {
@@ -821,7 +821,7 @@ impl Screen {
         } else {
             client_id
         };
-        let err_context = || format!("failed to create new tab for client {client_id:?}");
+        let err_context = || format!("failed to create new tab for client {client_id:?}",);
         let tab_index = self.get_new_tab_index();
         let position = self.tabs.len();
         let mut tab = Tab::new(
@@ -848,7 +848,7 @@ impl Screen {
             self.terminal_emulator_colors.clone(),
             self.terminal_emulator_color_codes.clone(),
         );
-        tab.apply_layout(layout, new_pids, tab_index, client_id)
+        tab.apply_layout(layout, new_ids, tab_index, client_id)
             .with_context(err_context)?;
         if self.session_is_mirrored {
             if let Some(active_tab) = self.get_active_tab_mut(client_id) {
@@ -1002,9 +1002,8 @@ impl Screen {
                             }
                         },
                     }
-                    self.update_tabs().with_context(|| {
-                        format!("failed to update active tabs name for client id: {client_id:?}")
-                    })
+                    self.update_tabs()
+                        .context("failed to update active tabs name for client id: {client_id:?}")
                 } else {
                     log::error!("Active tab not found for client id: {client_id:?}");
                     Ok(())
@@ -1092,7 +1091,6 @@ impl Screen {
         }
         Ok(())
     }
-
     pub fn change_mode_for_all_clients(&mut self, mode_info: ModeInfo) -> Result<()> {
         let err_context = || {
             format!(
@@ -1225,17 +1223,24 @@ pub(crate) fn screen_thread_main(
             ScreenInstruction::Render => {
                 screen.render()?;
             },
-            ScreenInstruction::NewPane(pid, client_or_tab_index) => {
+            ScreenInstruction::NewPane(
+                pid,
+                initial_pane_title,
+                should_float,
+                client_or_tab_index,
+            ) => {
                 match client_or_tab_index {
                     ClientOrTabIndex::ClientId(client_id) => {
                         active_tab_and_connected_client_id!(screen, client_id, |tab: &mut Tab,
                                                             client_id: ClientId| tab .new_pane(pid,
+                                                                                               initial_pane_title,
+                                                                                               should_float,
                                                                                                Some(client_id)),
                                                                                                ?);
                     },
                     ClientOrTabIndex::TabIndex(tab_index) => {
                         if let Some(active_tab) = screen.tabs.get_mut(&tab_index) {
-                            active_tab.new_pane(pid, None)?;
+                            active_tab.new_pane(pid, initial_pane_title, should_float, None)?;
                         } else {
                             log::error!("Tab index not found: {:?}", tab_index);
                         }
@@ -1270,44 +1275,22 @@ pub(crate) fn screen_thread_main(
 
                 screen.render()?;
             },
-            ScreenInstruction::ShowFloatingPanes(client_id) => {
+            ScreenInstruction::HorizontalSplit(pid, initial_pane_title, client_id) => {
                 active_tab_and_connected_client_id!(
                     screen,
                     client_id,
-                    |tab: &mut Tab, _client_id: ClientId| tab.show_floating_panes()
-                );
-                screen.unblock_input()?;
-                screen.update_tabs()?; // update tabs so that the ui indication will be send to the plugins
-
-                screen.render()?;
-            },
-            ScreenInstruction::HideFloatingPanes(client_id) => {
-                active_tab_and_connected_client_id!(
-                    screen,
-                    client_id,
-                    |tab: &mut Tab, _client_id: ClientId| tab.hide_floating_panes()
-                );
-                screen.unblock_input()?;
-                screen.update_tabs()?; // update tabs so that the ui indication will be send to the plugins
-
-                screen.render()?;
-            },
-            ScreenInstruction::HorizontalSplit(pid, client_id) => {
-                active_tab_and_connected_client_id!(
-                    screen,
-                    client_id,
-                    |tab: &mut Tab, client_id: ClientId| tab.horizontal_split(pid, client_id),
+                    |tab: &mut Tab, client_id: ClientId| tab.horizontal_split(pid, initial_pane_title, client_id),
                     ?
                 );
                 screen.unblock_input()?;
                 screen.update_tabs()?;
                 screen.render()?;
             },
-            ScreenInstruction::VerticalSplit(pid, client_id) => {
+            ScreenInstruction::VerticalSplit(pid, initial_pane_title, client_id) => {
                 active_tab_and_connected_client_id!(
                     screen,
                     client_id,
-                    |tab: &mut Tab, client_id: ClientId| tab.vertical_split(pid, client_id),
+                    |tab: &mut Tab, client_id: ClientId| tab.vertical_split(pid, initial_pane_title, client_id),
                     ?
                 );
                 screen.unblock_input()?;
@@ -1657,6 +1640,27 @@ pub(crate) fn screen_thread_main(
                 screen.update_tabs()?;
                 screen.unblock_input()?;
             },
+            ScreenInstruction::HoldPane(id, exit_status, run_command, client_id) => {
+                match client_id {
+                    Some(client_id) => {
+                        active_tab!(screen, client_id, |tab: &mut Tab| tab.hold_pane(
+                            id,
+                            exit_status,
+                            run_command
+                        ));
+                    },
+                    None => {
+                        for tab in screen.tabs.values_mut() {
+                            if tab.get_all_pane_ids().contains(&id) {
+                                tab.hold_pane(id, exit_status, run_command);
+                                break;
+                            }
+                        }
+                    },
+                }
+                screen.update_tabs()?;
+                screen.unblock_input()?;
+            },
             ScreenInstruction::UpdatePaneName(c, client_id) => {
                 active_tab_and_connected_client_id!(
                     screen,

zellij-server/src/tab/mod.rs

@@ -8,6 +8,7 @@ use copy_command::CopyCommand;
 use std::env::temp_dir;
 use uuid::Uuid;
 use zellij_utils::errors::prelude::*;
+use zellij_utils::input::command::RunCommand;
 use zellij_utils::position::{Column, Line};
 use zellij_utils::{position::Position, serde};
 
@@ -29,7 +30,6 @@ use crate::{
 };
 use serde::{Deserialize, Serialize};
 use std::cell::RefCell;
-use std::os::unix::io::RawFd;
 use std::rc::Rc;
 use std::sync::mpsc::channel;
 use std::time::Instant;
@@ -50,9 +50,9 @@ use zellij_utils::{
 macro_rules! resize_pty {
     ($pane:expr, $os_input:expr) => {
         if let PaneId::Terminal(ref pid) = $pane.pid() {
-            // FIXME: This `set_terminal_size_using_fd` call would be best in
+            // FIXME: This `set_terminal_size_using_terminal_id` call would be best in
             // `TerminalPane::reflow_lines`
-            $os_input.set_terminal_size_using_fd(
+            $os_input.set_terminal_size_using_terminal_id(
                 *pid,
                 $pane.get_content_columns() as u16,
                 $pane.get_content_rows() as u16,
@@ -89,7 +89,7 @@ pub(crate) struct Tab {
     pub style: Style,
     connected_clients: Rc<RefCell<HashSet<ClientId>>>,
     draw_pane_frames: bool,
-    pending_vte_events: HashMap<RawFd, Vec<VteBytes>>,
+    pending_vte_events: HashMap<u32, Vec<VteBytes>>,
     pub selecting_with_mouse: bool, // this is only pub for the tests TODO: remove this once we combine write_text_to_clipboard with render
     link_handler: Rc<RefCell<LinkHandler>>,
     clipboard_provider: ClipboardProvider,
@@ -100,6 +100,7 @@ pub(crate) struct Tab {
     last_mouse_hold_position: Option<Position>,
     terminal_emulator_colors: Rc<RefCell<Palette>>,
     terminal_emulator_color_codes: Rc<RefCell<HashMap<usize, String>>>,
+    pids_waiting_resize: HashSet<u32>, // u32 is the terminal_id
 }
 
 #[derive(Clone, Debug, Default, Serialize, Deserialize)]
@@ -127,7 +128,9 @@ pub trait Pane {
     fn set_geom_override(&mut self, pane_geom: PaneGeom);
     fn handle_pty_bytes(&mut self, bytes: VteBytes);
     fn cursor_coordinates(&self) -> Option<(usize, usize)>;
-    fn adjust_input_to_terminal(&self, input_bytes: Vec<u8>) -> Vec<u8>;
+    fn adjust_input_to_terminal(&mut self, _input_bytes: Vec<u8>) -> Option<AdjustedInput> {
+        None
+    }
     fn position_and_size(&self) -> PaneGeom;
     fn current_geom(&self) -> PaneGeom;
     fn geom_override(&self) -> Option<PaneGeom>;
@@ -351,6 +354,16 @@ pub trait Pane {
         // False by default (only terminal-panes support alternate mode)
         false
     }
+    fn hold(&mut self, _exit_status: Option<i32>, _run_command: RunCommand) {
+        // No-op by default, only terminal panes support holding
+    }
+}
+
+#[derive(Clone, Debug)]
+pub enum AdjustedInput {
+    WriteBytesToTerminal(Vec<u8>),
+    ReRunCommandInThisPane(RunCommand),
+    CloseThisPane,
 }
 
 impl Tab {
@@ -450,13 +463,14 @@ impl Tab {
             last_mouse_hold_position: None,
             terminal_emulator_colors,
             terminal_emulator_color_codes,
+            pids_waiting_resize: HashSet::new(),
         }
     }
 
     pub fn apply_layout(
         &mut self,
         layout: PaneLayout,
-        new_pids: Vec<RawFd>,
+        new_ids: Vec<u32>,
         tab_index: usize,
         client_id: ClientId,
     ) -> Result<()> {
@@ -481,7 +495,7 @@ impl Tab {
         let positions_in_layout = layout.position_panes_in_space(&free_space);
 
         let positions_and_size = positions_in_layout.iter();
-        let mut new_pids = new_pids.iter();
+        let mut new_ids = new_ids.iter();
 
         let mut focus_pane_id: Option<PaneId> = None;
         let mut set_focus_pane_id = |layout: &PaneLayout, pane_id: PaneId| {
@@ -516,27 +530,33 @@ impl Tab {
                 set_focus_pane_id(layout, PaneId::Plugin(pid));
             } else {
                 // there are still panes left to fill, use the pids we received in this method
-                let pid = new_pids.next().with_context(err_context)?; // if this crashes it means we got less pids than there are panes in this layout
-                let next_terminal_position = self.get_next_terminal_position();
-                let mut new_pane = TerminalPane::new(
-                    *pid,
-                    *position_and_size,
-                    self.style,
-                    next_terminal_position,
-                    layout.name.clone().unwrap_or_default(),
-                    self.link_handler.clone(),
-                    self.character_cell_size.clone(),
-                    self.sixel_image_store.clone(),
-                    self.terminal_emulator_colors.clone(),
-                    self.terminal_emulator_color_codes.clone(),
-                );
-                new_pane.set_borderless(layout.borderless);
-                self.tiled_panes
-                    .add_pane_with_existing_geom(PaneId::Terminal(*pid), Box::new(new_pane));
-                set_focus_pane_id(layout, PaneId::Terminal(*pid));
+                if let Some(pid) = new_ids.next() {
+                    let next_terminal_position = self.get_next_terminal_position();
+                    let initial_title = match &layout.run {
+                        Some(Run::Command(run_command)) => Some(run_command.to_string()),
+                        _ => None,
+                    };
+                    let mut new_pane = TerminalPane::new(
+                        *pid,
+                        *position_and_size,
+                        self.style,
+                        next_terminal_position,
+                        layout.name.clone().unwrap_or_default(),
+                        self.link_handler.clone(),
+                        self.character_cell_size.clone(),
+                        self.sixel_image_store.clone(),
+                        self.terminal_emulator_colors.clone(),
+                        self.terminal_emulator_color_codes.clone(),
+                        initial_title,
+                    );
+                    new_pane.set_borderless(layout.borderless);
+                    self.tiled_panes
+                        .add_pane_with_existing_geom(PaneId::Terminal(*pid), Box::new(new_pane));
+                    set_focus_pane_id(layout, PaneId::Terminal(*pid));
+                }
             }
         }
-        for unused_pid in new_pids {
+        for unused_pid in new_ids {
             // this is a bit of a hack and happens because we don't have any central location that
             // can query the screen as to how many panes it needs to create a layout
             // fixing this will require a bit of an architecture change
@@ -745,18 +765,10 @@ impl Tab {
                     }
                 },
                 None => {
-                    // there aren't any floating panes, we need to open a new one
-                    //
-                    // ************************************************************************************************
-                    // BEWARE - THIS IS NOT ATOMIC - this sends an instruction to the pty thread to open a new terminal
-                    // the pty thread will do its thing and eventually come back to the new_pane
-                    // method on this tab which will open a new floating pane because we just
-                    // toggled their visibility above us.
-                    // If the pty thread takes too long, weird things can happen...
-                    // ************************************************************************************************
-                    //
+                    let should_float = true;
                     let instruction = PtyInstruction::SpawnTerminal(
                         default_shell,
+                        Some(should_float),
                         ClientOrTabIndex::ClientId(client_id),
                     );
                     self.senders.send_to_pty(instruction).with_context(|| {
@@ -769,18 +781,18 @@ impl Tab {
         self.set_force_render();
         Ok(())
     }
-
-    pub fn show_floating_panes(&mut self) {
-        self.floating_panes.toggle_show_panes(true);
-        self.set_force_render();
-    }
-
-    pub fn hide_floating_panes(&mut self) {
-        self.floating_panes.toggle_show_panes(false);
-        self.set_force_render();
-    }
-
-    pub fn new_pane(&mut self, pid: PaneId, client_id: Option<ClientId>) -> Result<()> {
+    pub fn new_pane(
+        &mut self,
+        pid: PaneId,
+        initial_pane_title: Option<String>,
+        should_float: Option<bool>,
+        client_id: Option<ClientId>,
+    ) -> Result<()> {
+        match should_float {
+            Some(true) => self.floating_panes.toggle_show_panes(true),
+            Some(false) => self.floating_panes.toggle_show_panes(false),
+            None => {},
+        };
         self.close_down_to_max_terminals()
             .with_context(|| format!("failed to create new pane with id {pid:?}"))?;
         if self.floating_panes.panes_are_visible() {
@@ -798,6 +810,7 @@ impl Tab {
                         self.sixel_image_store.clone(),
                         self.terminal_emulator_colors.clone(),
                         self.terminal_emulator_color_codes.clone(),
+                        initial_pane_title,
                     );
                     new_pane.set_content_offset(Offset::frame(1)); // floating panes always have a frame
                     resize_pty!(new_pane, self.os_api);
@@ -823,6 +836,7 @@ impl Tab {
                         self.sixel_image_store.clone(),
                         self.terminal_emulator_colors.clone(),
                         self.terminal_emulator_color_codes.clone(),
+                        initial_pane_title,
                     );
                     self.tiled_panes.insert_pane(pid, Box::new(new_terminal));
                     self.should_clear_display_before_rendering = true;
@@ -841,7 +855,7 @@ impl Tab {
         match pid {
             PaneId::Terminal(pid) => {
                 let next_terminal_position = self.get_next_terminal_position(); // TODO: this is not accurate in this case
-                let new_pane = TerminalPane::new(
+                let mut new_pane = TerminalPane::new(
                     pid,
                     PaneGeom::default(), // the initial size will be set later
                     self.style,
@@ -852,7 +866,11 @@ impl Tab {
                     self.sixel_image_store.clone(),
                     self.terminal_emulator_colors.clone(),
                     self.terminal_emulator_color_codes.clone(),
+                    None,
                 );
+                new_pane.update_name("EDITING SCROLLBACK"); // we do this here and not in the
+                                                            // constructor so it won't be overrided
+                                                            // by the editor
                 let replaced_pane = if self.floating_panes.panes_are_visible() {
                     self.floating_panes
                         .replace_active_pane(Box::new(new_pane), client_id)
@@ -882,11 +900,14 @@ impl Tab {
         }
         Ok(())
     }
-
-    pub fn horizontal_split(&mut self, pid: PaneId, client_id: ClientId) -> Result<()> {
+    pub fn horizontal_split(
+        &mut self,
+        pid: PaneId,
+        initial_pane_title: Option<String>,
+        client_id: ClientId,
+    ) -> Result<()> {
         let err_context =
             || format!("failed to split pane {pid:?} horizontally for client {client_id}");
-
         if self.floating_panes.panes_are_visible() {
             return Ok(());
         }
@@ -909,6 +930,7 @@ impl Tab {
                     self.sixel_image_store.clone(),
                     self.terminal_emulator_colors.clone(),
                     self.terminal_emulator_color_codes.clone(),
+                    initial_pane_title,
                 );
                 self.tiled_panes
                     .split_pane_horizontally(pid, Box::new(new_terminal), client_id);
@@ -918,11 +940,14 @@ impl Tab {
         }
         Ok(())
     }
-
-    pub fn vertical_split(&mut self, pid: PaneId, client_id: ClientId) -> Result<()> {
+    pub fn vertical_split(
+        &mut self,
+        pid: PaneId,
+        initial_pane_title: Option<String>,
+        client_id: ClientId,
+    ) -> Result<()> {
         let err_context =
             || format!("failed to split pane {pid:?} vertically for client {client_id}");
-
         if self.floating_panes.panes_are_visible() {
             return Ok(());
         }
@@ -945,6 +970,7 @@ impl Tab {
                     self.sixel_image_store.clone(),
                     self.terminal_emulator_colors.clone(),
                     self.terminal_emulator_color_codes.clone(),
+                    initial_pane_title,
                 );
                 self.tiled_panes
                     .split_pane_vertically(pid, Box::new(new_terminal), client_id);
@@ -990,14 +1016,14 @@ impl Tab {
             self.tiled_panes.get_active_pane_id(client_id)
         }
     }
-    fn get_active_terminal_id(&self, client_id: ClientId) -> Option<RawFd> {
+    fn get_active_terminal_id(&self, client_id: ClientId) -> Option<u32> {
         if let Some(PaneId::Terminal(pid)) = self.get_active_pane_id(client_id) {
             Some(pid)
         } else {
             None
         }
     }
-    pub fn has_terminal_pid(&self, pid: RawFd) -> bool {
+    pub fn has_terminal_pid(&self, pid: u32) -> bool {
         self.tiled_panes.panes_contain(&PaneId::Terminal(pid))
             || self.floating_panes.panes_contain(&PaneId::Terminal(pid))
             || self
@@ -1005,9 +1031,8 @@ impl Tab {
                 .values()
                 .any(|s_p| s_p.pid() == PaneId::Terminal(pid))
     }
-    pub fn handle_pty_bytes(&mut self, pid: RawFd, bytes: VteBytes) -> Result<()> {
+    pub fn handle_pty_bytes(&mut self, pid: u32, bytes: VteBytes) -> Result<()> {
         let err_context = || format!("failed to handle pty bytes from fd {pid}");
-
         if let Some(terminal_output) = self
             .tiled_panes
             .get_pane_mut(PaneId::Terminal(pid))
@@ -1034,8 +1059,7 @@ impl Tab {
         }
         self.process_pty_bytes(pid, bytes).with_context(err_context)
     }
-
-    pub fn process_pending_vte_events(&mut self, pid: RawFd) -> Result<()> {
+    pub fn process_pending_vte_events(&mut self, pid: u32) -> Result<()> {
         if let Some(pending_vte_events) = self.pending_vte_events.get_mut(&pid) {
             let vte_events: Vec<VteBytes> = pending_vte_events.drain(..).collect();
             for vte_event in vte_events {
@@ -1045,10 +1069,8 @@ impl Tab {
         }
         Ok(())
     }
-
-    fn process_pty_bytes(&mut self, pid: RawFd, bytes: VteBytes) -> Result<()> {
+    fn process_pty_bytes(&mut self, pid: u32, bytes: VteBytes) -> Result<()> {
         let err_context = || format!("failed to process pty bytes from pid {pid}");
-
         if let Some(terminal_output) = self
             .tiled_panes
             .get_pane_mut(PaneId::Terminal(pid))
@@ -1059,6 +1081,9 @@ impl Tab {
                     .find(|s_p| s_p.pid() == PaneId::Terminal(pid))
             })
         {
+            if self.pids_waiting_resize.remove(&pid) {
+                resize_pty!(terminal_output, self.os_api);
+            }
             terminal_output.handle_pty_bytes(bytes);
             let messages_to_pty = terminal_output.drain_messages_to_pty();
             let clipboard_update = terminal_output.drain_clipboard_update();
@@ -1149,19 +1174,34 @@ impl Tab {
             PaneId::Terminal(active_terminal_id) => {
                 let active_terminal = self
                     .floating_panes
-                    .get(&pane_id)
-                    .or_else(|| self.tiled_panes.get_pane(pane_id))
-                    .or_else(|| self.suppressed_panes.get(&pane_id))
+                    .get_mut(&pane_id)
+                    .or_else(|| self.tiled_panes.get_pane_mut(pane_id))
+                    .or_else(|| self.suppressed_panes.get_mut(&pane_id))
                     .ok_or_else(|| anyhow!(format!("failed to find pane with id {pane_id:?}")))
                     .with_context(err_context)?;
-                let adjusted_input = active_terminal.adjust_input_to_terminal(input_bytes);
-
-                self.senders
-                    .send_to_pty_writer(PtyWriteInstruction::Write(
-                        adjusted_input,
-                        active_terminal_id,
-                    ))
-                    .with_context(err_context)?;
+                match active_terminal.adjust_input_to_terminal(input_bytes) {
+                    Some(AdjustedInput::WriteBytesToTerminal(adjusted_input)) => {
+                        self.senders
+                            .send_to_pty_writer(PtyWriteInstruction::Write(
+                                adjusted_input,
+                                active_terminal_id,
+                            ))
+                            .with_context(err_context)?;
+                    },
+                    Some(AdjustedInput::ReRunCommandInThisPane(command)) => {
+                        self.pids_waiting_resize.insert(active_terminal_id);
+                        self.senders
+                            .send_to_pty(PtyInstruction::ReRunCommandInPane(
+                                PaneId::Terminal(active_terminal_id),
+                                command,
+                            ))
+                            .with_context(err_context)?;
+                    },
+                    Some(AdjustedInput::CloseThisPane) => {
+                        self.close_pane(PaneId::Terminal(active_terminal_id), false);
+                    },
+                    None => {},
+                }
             },
             PaneId::Plugin(pid) => {
                 for key in parse_keys(&input_bytes) {
@@ -1686,6 +1726,13 @@ impl Tab {
             closed_pane
         }
     }
+    pub fn hold_pane(&mut self, id: PaneId, exit_status: Option<i32>, run_command: RunCommand) {
+        if self.floating_panes.panes_contain(&id) {
+            self.floating_panes.hold_pane(id, exit_status, run_command);
+        } else {
+            self.tiled_panes.hold_pane(id, exit_status, run_command);
+        }
+    }
     pub fn replace_pane_with_suppressed_pane(&mut self, pane_id: PaneId) -> Option<Box<dyn Pane>> {
         self.suppressed_panes
             .remove(&pane_id)
@@ -2335,7 +2382,6 @@ impl Tab {
         let err_context = || {
             format!("failed to handle left mouse hold at position {position_on_screen:?} for client {client_id}")
         };
-
         // return value indicates whether we should trigger a render
         // determine if event is repeated to enable smooth scrolling
         let is_repeated = if let Some(last_position) = self.last_mouse_hold_position {

zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__resize_whole_tab_while_floting_pane_is_suppressed.snap

@@ -1,9 +1,9 @@
 ---
 source: zellij-server/src/tab/./unit/tab_integration_tests.rs
-assertion_line: 1474
+assertion_line: 1801
 expression: snapshot
 ---
-00 (C): ┌ Pane #1 ────────────────────┌ Pane #3 ─────────────────────────────────────────────────┐─────────┐                     
+00 (C): ┌ Pane #1 ────────────────────┌ EDITING SCROLLBACK ──────────────────────────────────────┐─────────┐                     
 01 (C): │                             │                                                          │         │                     
 02 (C): │                             │                                                          │         │                     
 03 (C): │                             │                                                          │         │                     

zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__resize_whole_tab_while_tiled_pane_is_suppressed.snap

@@ -1,9 +1,9 @@
 ---
 source: zellij-server/src/tab/./unit/tab_integration_tests.rs
-assertion_line: 1444
+assertion_line: 1771
 expression: snapshot
 ---
-00 (C): ┌ Pane #2 ─────────────────────────────────────────────────────────────────────────────────────────┐                     
+00 (C): ┌ EDITING SCROLLBACK ──────────────────────────────────────────────────────────────────────────────┐                     
 01 (C): │                                                                                                  │                     
 02 (C): │                                                                                                  │                     
 03 (C): │                                                                                                  │                     

zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__suppress_floating_pane.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/tab/./unit/tab_integration_tests.rs
-assertion_line: 1288
+assertion_line: 1639
 expression: snapshot
 ---
 00 (C): ┌ Pane #1 ──────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
@@ -8,7 +8,7 @@ expression: snapshot
 02 (C): │                                                                                                                       │
 03 (C): │                                                                                                                       │
 04 (C): │                                                                                                                       │
-05 (C): │                             ┌ Pane #3 ─────────────────────────────────────────────────┐                              │
+05 (C): │                             ┌ EDITING SCROLLBACK ──────────────────────────────────────┐                              │
 06 (C): │                             │                                                          │                              │
 07 (C): │                             │                                                          │                              │
 08 (C): │                             │                                                          │                              │

zellij-server/src/tab/unit/snapshots/zellij_server__tab__tab_integration_tests__suppress_tiled_pane.snap

@@ -1,9 +1,9 @@
 ---
 source: zellij-server/src/tab/./unit/tab_integration_tests.rs
-assertion_line: 1259
+assertion_line: 1613
 expression: snapshot
 ---
-00 (C): ┌ Pane #2 ──────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
+00 (C): ┌ EDITING SCROLLBACK ───────────────────────────────────────────────────────────────────────────────────────────────────┐
 01 (C): │                                                                                                                       │
 02 (C): │                                                                                                                       │
 03 (C): │                                                                                                                       │

zellij-server/src/tab/unit/tab_integration_tests.rs

@@ -4,7 +4,7 @@ use crate::screen::CopyOptions;
 use crate::Arc;
 use crate::Mutex;
 use crate::{
-    os_input_output::{AsyncReader, Pid, ServerOsApi},
+    os_input_output::{AsyncReader, Pid, ServerOsApi, SpawnTerminalError},
     panes::PaneId,
     thread_bus::ThreadSenders,
     ClientId,
@@ -30,7 +30,7 @@ use zellij_utils::nix;
 
 use zellij_utils::{
     data::{InputMode, ModeInfo, Palette, Style},
-    input::command::TerminalAction,
+    input::command::{RunCommand, TerminalAction},
     interprocess::local_socket::LocalSocketStream,
     ipc::{ClientToServerMsg, ServerToClientMsg},
 };
@@ -41,15 +41,15 @@ struct FakeInputOutput {
 }
 
 impl ServerOsApi for FakeInputOutput {
-    fn set_terminal_size_using_fd(&self, _fd: RawFd, _cols: u16, _rows: u16) {
+    fn set_terminal_size_using_terminal_id(&self, _id: u32, _cols: u16, _rows: u16) {
         // noop
     }
     fn spawn_terminal(
         &self,
         _file_to_open: TerminalAction,
-        _quit_cb: Box<dyn Fn(PaneId) + Send>,
+        _quit_db: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>,
         _default_editor: Option<PathBuf>,
-    ) -> Result<(RawFd, RawFd), &'static str> {
+    ) -> Result<(u32, RawFd, RawFd), SpawnTerminalError> {
         unimplemented!()
     }
     fn read_from_tty_stdout(&self, _fd: RawFd, _buf: &mut [u8]) -> Result<usize, nix::Error> {
@@ -58,10 +58,10 @@ impl ServerOsApi for FakeInputOutput {
     fn async_file_reader(&self, _fd: RawFd) -> Box<dyn AsyncReader> {
         unimplemented!()
     }
-    fn write_to_tty_stdin(&self, _fd: RawFd, _buf: &[u8]) -> Result<usize, nix::Error> {
+    fn write_to_tty_stdin(&self, _id: u32, _buf: &[u8]) -> Result<usize, nix::Error> {
         unimplemented!()
     }
-    fn tcdrain(&self, _fd: RawFd) -> Result<(), nix::Error> {
+    fn tcdrain(&self, _id: u32) -> Result<(), nix::Error> {
         unimplemented!()
     }
     fn kill(&self, _pid: Pid) -> Result<(), nix::Error> {
@@ -103,6 +103,17 @@ impl ServerOsApi for FakeInputOutput {
         };
         self.file_dumps.lock().unwrap().insert(f, buf);
     }
+    fn re_run_command_in_terminal(
+        &self,
+        _terminal_id: u32,
+        _run_command: RunCommand,
+        _quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
+    ) -> Result<(RawFd, RawFd), SpawnTerminalError> {
+        unimplemented!()
+    }
+    fn clear_terminal_id(&self, _terminal_id: u32) {
+        unimplemented!()
+    }
 }
 
 struct MockPtyInstructionBus {
@@ -266,7 +277,7 @@ fn create_new_tab_with_layout(size: Size, default_mode: ModeInfo, layout: &str)
         .extract_run_instructions()
         .iter()
         .enumerate()
-        .map(|(i, _)| i as i32)
+        .map(|(i, _)| i as u32)
         .collect();
     tab.apply_layout(tab_layout, pane_ids, index, client_id)
         .unwrap();
@@ -491,7 +502,8 @@ fn dump_screen() {
         file_dumps: map.clone(),
     });
     let new_pane_id = PaneId::Terminal(2);
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(2, Vec::from("scratch".as_bytes()))
         .unwrap();
     let file = "/tmp/log.sh";
@@ -514,7 +526,8 @@ fn new_floating_pane() {
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -541,7 +554,8 @@ fn floating_panes_persist_across_toggles() {
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.toggle_floating_panes(client_id, None).unwrap();
     // here we send bytes to the pane when it's not visible to make sure they're still handled and
     // we see them once we toggle the panes back
@@ -572,7 +586,8 @@ fn toggle_floating_panes_off() {
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -600,7 +615,8 @@ fn toggle_floating_panes_on() {
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -633,11 +649,16 @@ fn five_new_floating_panes() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -672,7 +693,8 @@ fn increase_floating_pane_size() {
     let new_pane_id_1 = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -700,7 +722,8 @@ fn decrease_floating_pane_size() {
     let new_pane_id_1 = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -728,7 +751,8 @@ fn resize_floating_pane_left() {
     let new_pane_id_1 = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -756,7 +780,8 @@ fn resize_floating_pane_right() {
     let new_pane_id_1 = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -784,7 +809,8 @@ fn resize_floating_pane_up() {
     let new_pane_id_1 = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -812,7 +838,8 @@ fn resize_floating_pane_down() {
     let new_pane_id_1 = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -844,11 +871,16 @@ fn move_floating_pane_focus_left() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -894,11 +926,16 @@ fn move_floating_pane_focus_right() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -945,11 +982,16 @@ fn move_floating_pane_focus_up() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -995,11 +1037,16 @@ fn move_floating_pane_focus_down() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1046,11 +1093,16 @@ fn move_floating_pane_focus_with_mouse() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1099,11 +1151,16 @@ fn move_pane_focus_with_mouse_to_non_floating_pane() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1152,11 +1209,16 @@ fn drag_pane_with_mouse() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1205,11 +1267,16 @@ fn mark_text_inside_floating_pane() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1266,11 +1333,16 @@ fn resize_tab_with_floating_panes() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1314,11 +1386,16 @@ fn shrink_whole_tab_with_floating_panes_horizontally_and_vertically() {
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1359,11 +1436,16 @@ fn shrink_whole_tab_with_floating_panes_horizontally_and_vertically_and_expand_b
     let new_pane_id_5 = PaneId::Terminal(6);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id_1, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_2, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_3, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_4, Some(client_id)).unwrap();
-    tab.new_pane(new_pane_id_5, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id_1, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_2, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_3, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_4, None, None, Some(client_id))
+        .unwrap();
+    tab.new_pane(new_pane_id_5, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1404,7 +1486,8 @@ fn embed_floating_pane() {
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am scratch terminal".as_bytes()),
@@ -1431,7 +1514,8 @@ fn float_embedded_pane() {
     let mut tab = create_new_tab(size, ModeInfo::default());
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am an embedded pane".as_bytes()),
@@ -1533,7 +1617,8 @@ fn rename_floating_pane() {
     let mut tab = create_new_tab(size, ModeInfo::default());
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.handle_pty_bytes(
         2,
         Vec::from("\n\n\n                   I am a floating pane".as_bytes()),
@@ -1618,7 +1703,8 @@ fn move_floating_pane_with_sixel_image() {
     let mut output = Output::new(sixel_image_store.clone(), character_cell_size);
 
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     let fixture = read_fixture("sixel-image-500px.six");
     tab.handle_pty_bytes(2, fixture).unwrap();
     tab.handle_left_click(&Position::new(5, 71), client_id)
@@ -1655,7 +1741,8 @@ fn floating_pane_above_sixel_image() {
     let mut output = Output::new(sixel_image_store.clone(), character_cell_size);
 
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     let fixture = read_fixture("sixel-image-500px.six");
     tab.handle_pty_bytes(1, fixture).unwrap();
     tab.handle_left_click(&Position::new(5, 71), client_id)
@@ -1711,7 +1798,8 @@ fn suppress_floating_pane() {
     let mut output = Output::default();
 
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.suppress_active_pane(editor_pane_id, client_id).unwrap();
     tab.handle_pty_bytes(3, Vec::from("\n\n\nI am an editor pane".as_bytes()))
         .unwrap();
@@ -1764,7 +1852,8 @@ fn close_suppressing_floating_pane() {
     let mut output = Output::default();
 
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.suppress_active_pane(editor_pane_id, client_id).unwrap();
     tab.handle_pty_bytes(3, Vec::from("\n\n\nI am an editor pane".as_bytes()))
         .unwrap();
@@ -1821,7 +1910,8 @@ fn suppress_floating_pane_embed_it_and_close_it() {
     let mut output = Output::default();
 
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.suppress_active_pane(editor_pane_id, client_id).unwrap();
     tab.handle_pty_bytes(3, Vec::from("\n\n\nI am an editor pane".as_bytes()))
         .unwrap();
@@ -1879,7 +1969,8 @@ fn resize_whole_tab_while_floting_pane_is_suppressed() {
     let mut output = Output::default();
 
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
     tab.suppress_active_pane(editor_pane_id, client_id).unwrap();
     tab.handle_pty_bytes(3, Vec::from("\n\n\nI am an editor pane".as_bytes()))
         .unwrap();
@@ -1978,7 +2069,8 @@ fn enter_search_floating_pane() {
     let new_pane_id = PaneId::Terminal(2);
     let mut output = Output::default();
     tab.toggle_floating_panes(client_id, None).unwrap();
-    tab.new_pane(new_pane_id, Some(client_id)).unwrap();
+    tab.new_pane(new_pane_id, None, None, Some(client_id))
+        .unwrap();
 
     let pane_content = read_fixture("grid_copy");
     tab.handle_pty_bytes(2, pane_content).unwrap();

zellij-server/src/terminal_bytes.rs

@@ -31,6 +31,7 @@ impl From<std::io::Result<usize>> for ReadResult {
 
 pub(crate) struct TerminalBytes {
     pid: RawFd,
+    terminal_id: u32,
     senders: ThreadSenders,
     async_reader: Box<dyn AsyncReader>,
     debug: bool,
@@ -47,9 +48,11 @@ impl TerminalBytes {
         senders: ThreadSenders,
         os_input: Box<dyn ServerOsApi>,
         debug: bool,
+        terminal_id: u32,
     ) -> Self {
         TerminalBytes {
             pid,
+            terminal_id,
             senders,
             debug,
             async_reader: os_input.async_file_reader(pid),
@@ -77,7 +80,6 @@ impl TerminalBytes {
         let mut buf = [0u8; 65536];
         loop {
             match self.deadline_read(&mut buf).await {
-                // match deadline_read(async_reader.as_mut(), self.render_deadline, &mut buf).await {
                 ReadResult::Ok(0) | ReadResult::Err(_) => break, // EOF or error
                 ReadResult::Timeout => {
                     let time_to_send_render =
@@ -93,7 +95,7 @@ impl TerminalBytes {
                         let _ = debug_to_file(bytes, self.pid);
                     }
                     self.async_send_to_screen(ScreenInstruction::PtyBytes(
-                        self.pid,
+                        self.terminal_id,
                         bytes.to_vec(),
                     ))
                     .await;

zellij-server/src/ui/pane_boundaries_frame.rs

@@ -61,6 +61,12 @@ fn background_color(characters: &str, color: Option<PaletteColor>) -> Vec<Termin
     colored_string
 }
 
+#[derive(Debug, Clone, Copy, PartialEq)]
+enum ExitStatus {
+    Code(i32),
+    Exited,
+}
+
 pub struct FrameParams {
     pub focused_client: Option<ClientId>,
     pub is_main_client: bool,
@@ -81,6 +87,7 @@ pub struct PaneFrame {
     pub is_main_client: bool,
     pub other_cursors_exist_in_session: bool,
     pub other_focused_clients: Vec<ClientId>,
+    exit_status: Option<ExitStatus>,
 }
 
 impl PaneFrame {
@@ -100,8 +107,15 @@ impl PaneFrame {
             is_main_client: frame_params.is_main_client,
             other_focused_clients: frame_params.other_focused_clients,
             other_cursors_exist_in_session: frame_params.other_cursors_exist_in_session,
+            exit_status: None,
         }
     }
+    pub fn add_exit_status(&mut self, exit_status: Option<i32>) {
+        self.exit_status = match exit_status {
+            Some(exit_status) => Some(ExitStatus::Code(exit_status)),
+            None => Some(ExitStatus::Exited),
+        };
+    }
     fn client_cursor(&self, client_id: ClientId) -> Vec<TerminalCharacter> {
         let color = client_id_to_colors(client_id, self.style.colors);
         background_color(" ", color.map(|c| c.0))
@@ -594,6 +608,65 @@ impl PaneFrame {
             .or_else(|| Some(self.title_line_without_middle()))
             .unwrap()
     }
+    fn render_held_undertitle(&self) -> Vec<TerminalCharacter> {
+        let max_undertitle_length = self.geom.cols.saturating_sub(2); // 2 for the left and right corners
+        let exit_status = self.exit_status.unwrap(); // unwrap is safe because we only call this if
+
+        let (mut first_part, first_part_len) = self.first_held_title_part_full(exit_status);
+        let mut left_boundary =
+            foreground_color(self.get_corner(boundary_type::BOTTOM_LEFT), self.color);
+        let mut right_boundary =
+            foreground_color(self.get_corner(boundary_type::BOTTOM_RIGHT), self.color);
+        if self.is_main_client {
+            let (mut second_part, second_part_len) = self.second_held_title_part_full();
+            let full_text_len = first_part_len + second_part_len;
+            if full_text_len <= max_undertitle_length {
+                // render exit status and tips
+                let mut padding = String::new();
+                for _ in full_text_len..max_undertitle_length {
+                    padding.push_str(boundary_type::HORIZONTAL);
+                }
+                let mut ret = vec![];
+                ret.append(&mut left_boundary);
+                ret.append(&mut first_part);
+                ret.append(&mut second_part);
+                ret.append(&mut foreground_color(&padding, self.color));
+                ret.append(&mut right_boundary);
+                ret
+            } else if first_part_len <= max_undertitle_length {
+                // render only exit status
+                let mut padding = String::new();
+                for _ in first_part_len..max_undertitle_length {
+                    padding.push_str(boundary_type::HORIZONTAL);
+                }
+                let mut ret = vec![];
+                ret.append(&mut left_boundary);
+                ret.append(&mut first_part);
+                ret.append(&mut foreground_color(&padding, self.color));
+                ret.append(&mut right_boundary);
+                ret
+            } else {
+                self.empty_undertitle(max_undertitle_length)
+            }
+        } else {
+            if first_part_len <= max_undertitle_length {
+                // render first part
+                let full_text_len = first_part_len;
+                let mut padding = String::new();
+                for _ in full_text_len..max_undertitle_length {
+                    padding.push_str(boundary_type::HORIZONTAL);
+                }
+                let mut ret = vec![];
+                ret.append(&mut left_boundary);
+                ret.append(&mut first_part);
+                ret.append(&mut foreground_color(&padding, self.color));
+                ret.append(&mut right_boundary);
+                ret
+            } else {
+                self.empty_undertitle(max_undertitle_length)
+            }
+        }
+    }
     pub fn render(&self) -> (Vec<CharacterChunk>, Option<String>) {
         let mut character_chunks = vec![];
         for row in 0..self.geom.rows {
@@ -605,24 +678,30 @@ impl PaneFrame {
                 character_chunks.push(CharacterChunk::new(title, x, y));
             } else if row == self.geom.rows - 1 {
                 // bottom row
-                let mut bottom_row = vec![];
-                for col in 0..self.geom.cols {
-                    let boundary = if col == 0 {
-                        // bottom left corner
-                        self.get_corner(boundary_type::BOTTOM_LEFT)
-                    } else if col == self.geom.cols - 1 {
-                        // bottom right corner
-                        self.get_corner(boundary_type::BOTTOM_RIGHT)
-                    } else {
-                        boundary_type::HORIZONTAL
-                    };
+                if self.exit_status.is_some() {
+                    let x = self.geom.x;
+                    let y = self.geom.y + row;
+                    character_chunks.push(CharacterChunk::new(self.render_held_undertitle(), x, y));
+                } else {
+                    let mut bottom_row = vec![];
+                    for col in 0..self.geom.cols {
+                        let boundary = if col == 0 {
+                            // bottom left corner
+                            self.get_corner(boundary_type::BOTTOM_LEFT)
+                        } else if col == self.geom.cols - 1 {
+                            // bottom right corner
+                            self.get_corner(boundary_type::BOTTOM_RIGHT)
+                        } else {
+                            boundary_type::HORIZONTAL
+                        };
 
-                    let mut boundary_character = foreground_color(boundary, self.color);
-                    bottom_row.append(&mut boundary_character);
+                        let mut boundary_character = foreground_color(boundary, self.color);
+                        bottom_row.append(&mut boundary_character);
+                    }
+                    let x = self.geom.x;
+                    let y = self.geom.y + row;
+                    character_chunks.push(CharacterChunk::new(bottom_row, x, y));
                 }
-                let x = self.geom.x;
-                let y = self.geom.y + row;
-                character_chunks.push(CharacterChunk::new(bottom_row, x, y));
             } else {
                 let boundary_character_left = foreground_color(boundary_type::VERTICAL, self.color);
                 let boundary_character_right =
@@ -639,4 +718,106 @@ impl PaneFrame {
         }
         (character_chunks, None)
     }
+    fn first_held_title_part_full(
+        &self,
+        exit_status: ExitStatus,
+    ) -> (Vec<TerminalCharacter>, usize) {
+        // (title part, length)
+        match exit_status {
+            ExitStatus::Code(exit_code) => {
+                let mut first_part = vec![];
+                let left_bracket = " [ ";
+                let exited_text = "EXIT CODE: ";
+                let exit_code_text = format!("{}", exit_code);
+                let exit_code_color = if exit_code == 0 {
+                    self.style.colors.green
+                } else {
+                    self.style.colors.red
+                };
+                let right_bracket = " ] ";
+                first_part.append(&mut foreground_color(left_bracket, self.color));
+                first_part.append(&mut foreground_color(exited_text, self.color));
+                first_part.append(&mut foreground_color(
+                    &exit_code_text,
+                    Some(exit_code_color),
+                ));
+                first_part.append(&mut foreground_color(right_bracket, self.color));
+                (
+                    first_part,
+                    left_bracket.len()
+                        + exited_text.len()
+                        + exit_code_text.len()
+                        + right_bracket.len(),
+                )
+            },
+            ExitStatus::Exited => {
+                let mut first_part = vec![];
+                let left_bracket = " [ ";
+                let exited_text = "EXITED";
+                let right_bracket = " ] ";
+                first_part.append(&mut foreground_color(left_bracket, self.color));
+                first_part.append(&mut foreground_color(
+                    exited_text,
+                    Some(self.style.colors.red),
+                ));
+                first_part.append(&mut foreground_color(right_bracket, self.color));
+                (
+                    first_part,
+                    left_bracket.len() + exited_text.len() + right_bracket.len(),
+                )
+            },
+        }
+    }
+    fn second_held_title_part_full(&self) -> (Vec<TerminalCharacter>, usize) {
+        // (title part, length)
+        let mut second_part = vec![];
+        let left_enter_bracket = "<";
+        let enter_text = "ENTER";
+        let right_enter_bracket = ">";
+        let enter_tip = " to re-run, ";
+        let left_break_bracket = "<";
+        let break_text = "Ctrl-c";
+        let right_break_bracket = ">";
+        let break_tip = " to exit ";
+        second_part.append(&mut foreground_color(left_enter_bracket, self.color));
+        second_part.append(&mut foreground_color(
+            enter_text,
+            Some(self.style.colors.orange),
+        ));
+        second_part.append(&mut foreground_color(right_enter_bracket, self.color));
+        second_part.append(&mut foreground_color(enter_tip, self.color));
+        second_part.append(&mut foreground_color(left_break_bracket, self.color));
+        second_part.append(&mut foreground_color(
+            break_text,
+            Some(self.style.colors.orange),
+        ));
+        second_part.append(&mut foreground_color(right_break_bracket, self.color));
+        second_part.append(&mut foreground_color(break_tip, self.color));
+        (
+            second_part,
+            left_enter_bracket.len()
+                + enter_text.len()
+                + right_enter_bracket.len()
+                + enter_tip.len()
+                + left_break_bracket.len()
+                + break_text.len()
+                + right_break_bracket.len()
+                + break_tip.len(),
+        )
+    }
+    fn empty_undertitle(&self, max_undertitle_length: usize) -> Vec<TerminalCharacter> {
+        let mut left_boundary =
+            foreground_color(self.get_corner(boundary_type::BOTTOM_LEFT), self.color);
+        let mut right_boundary =
+            foreground_color(self.get_corner(boundary_type::BOTTOM_RIGHT), self.color);
+        let mut ret = vec![];
+        let mut padding = String::new();
+        for _ in 0..max_undertitle_length {
+            padding.push_str(boundary_type::HORIZONTAL);
+        }
+        ret.append(&mut left_boundary);
+        ret.append(&mut foreground_color(&padding, self.color));
+        ret.append(&mut right_boundary);
+        ret
+    }
 }

zellij-server/src/unit/os_input_output_tests.rs

@@ -38,6 +38,7 @@ fn get_cwd() {
     let server = ServerOsInputOutput {
         orig_termios: Arc::new(Mutex::new(test_termios)),
         client_senders: Arc::default(),
+        terminal_id_to_raw_fd: Arc::default(),
     };
 
     let pid = nix::unistd::getpid();

zellij-server/src/unit/screen_tests.rs

@@ -2,7 +2,7 @@ use super::{screen_thread_main, CopyOptions, Screen, ScreenInstruction};
 use crate::panes::PaneId;
 use crate::{
     channels::SenderWithContext,
-    os_input_output::{AsyncReader, Pid, ServerOsApi},
+    os_input_output::{AsyncReader, Pid, ServerOsApi, SpawnTerminalError},
     route::route_action,
     thread_bus::Bus,
     ClientId, ServerInstruction, SessionMetaData, ThreadSenders,
@@ -12,7 +12,7 @@ use std::path::PathBuf;
 use zellij_utils::cli::CliAction;
 use zellij_utils::errors::ErrorContext;
 use zellij_utils::input::actions::{Action, Direction, ResizeDirection};
-use zellij_utils::input::command::TerminalAction;
+use zellij_utils::input::command::{RunCommand, TerminalAction};
 use zellij_utils::input::layout::{PaneLayout, SplitDirection};
 use zellij_utils::input::options::Options;
 use zellij_utils::ipc::IpcReceiverWithContext;
@@ -126,15 +126,15 @@ struct FakeInputOutput {
 }
 
 impl ServerOsApi for FakeInputOutput {
-    fn set_terminal_size_using_fd(&self, _fd: RawFd, _cols: u16, _rows: u16) {
+    fn set_terminal_size_using_terminal_id(&self, _terminal_id: u32, _cols: u16, _rows: u16) {
         // noop
     }
     fn spawn_terminal(
         &self,
         _file_to_open: TerminalAction,
-        _quit_db: Box<dyn Fn(PaneId) + Send>,
+        _quit_db: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>,
         _default_editor: Option<PathBuf>,
-    ) -> Result<(RawFd, RawFd), &'static str> {
+    ) -> Result<(u32, RawFd, RawFd), SpawnTerminalError> {
         unimplemented!()
     }
     fn read_from_tty_stdout(&self, _fd: RawFd, _buf: &mut [u8]) -> Result<usize, nix::Error> {
@@ -143,10 +143,10 @@ impl ServerOsApi for FakeInputOutput {
     fn async_file_reader(&self, _fd: RawFd) -> Box<dyn AsyncReader> {
         unimplemented!()
     }
-    fn write_to_tty_stdin(&self, _fd: RawFd, _buf: &[u8]) -> Result<usize, nix::Error> {
+    fn write_to_tty_stdin(&self, _id: u32, _buf: &[u8]) -> Result<usize, nix::Error> {
         unimplemented!()
     }
-    fn tcdrain(&self, _fd: RawFd) -> Result<(), nix::Error> {
+    fn tcdrain(&self, _id: u32) -> Result<(), nix::Error> {
         unimplemented!()
     }
     fn kill(&self, _pid: Pid) -> Result<(), nix::Error> {
@@ -195,6 +195,17 @@ impl ServerOsApi for FakeInputOutput {
                 .insert(filename, contents);
         }
     }
+    fn re_run_command_in_terminal(
+        &self,
+        _terminal_id: u32,
+        _run_command: RunCommand,
+        _quit_cb: Box<dyn Fn(PaneId, Option<i32>, RunCommand) + Send>, // u32 is the exit status
+    ) -> Result<(RawFd, RawFd), SpawnTerminalError> {
+        unimplemented!()
+    }
+    fn clear_terminal_id(&self, _terminal_id: u32) {
+        unimplemented!()
+    }
 }
 
 fn create_new_screen(size: Size) -> Screen {
@@ -272,7 +283,7 @@ impl MockScreen {
         let pane_count = pane_layout.extract_run_instructions().len();
         let mut pane_ids = vec![];
         for i in 0..pane_count {
-            pane_ids.push(i as i32);
+            pane_ids.push(i as u32);
         }
         let _ = self.to_screen.send(ScreenInstruction::NewTab(
             pane_layout,
@@ -285,7 +296,7 @@ impl MockScreen {
         let pane_count = tab_layout.extract_run_instructions().len();
         let mut pane_ids = vec![];
         for i in 0..pane_count {
-            pane_ids.push(i as i32);
+            pane_ids.push(i as u32);
         }
         let _ = self.to_screen.send(ScreenInstruction::NewTab(
             tab_layout,
@@ -412,7 +423,7 @@ macro_rules! log_actions_in_thread {
     };
 }
 
-fn new_tab(screen: &mut Screen, pid: i32) {
+fn new_tab(screen: &mut Screen, pid: u32) {
     let client_id = 1;
     screen
         .new_tab(PaneLayout::default(), vec![pid], client_id)
@@ -746,7 +757,9 @@ fn switch_to_tab_with_fullscreen() {
     new_tab(&mut screen, 1);
     {
         let active_tab = screen.get_active_tab_mut(1).unwrap();
-        active_tab.new_pane(PaneId::Terminal(2), Some(1)).unwrap();
+        active_tab
+            .new_pane(PaneId::Terminal(2), None, None, Some(1))
+            .unwrap();
         active_tab.toggle_active_pane_fullscreen(1);
     }
     new_tab(&mut screen, 2);
@@ -859,7 +872,9 @@ fn attach_after_first_tab_closed() {
     new_tab(&mut screen, 1);
     {
         let active_tab = screen.get_active_tab_mut(1).unwrap();
-        active_tab.new_pane(PaneId::Terminal(2), Some(1)).unwrap();
+        active_tab
+            .new_pane(PaneId::Terminal(2), None, None, Some(1))
+            .unwrap();
         active_tab.toggle_active_pane_fullscreen(1);
     }
     new_tab(&mut screen, 2);
@@ -1802,7 +1817,7 @@ pub fn send_cli_new_pane_action_with_default_parameters() {
         direction: None,
         command: None,
         cwd: None,
-        floating: None,
+        floating: false,
     };
     send_cli_action_to_server(
         &session_metadata,
@@ -1839,7 +1854,7 @@ pub fn send_cli_new_pane_action_with_split_direction() {
         direction: Some(Direction::Right),
         command: None,
         cwd: None,
-        floating: None,
+        floating: false,
     };
     send_cli_action_to_server(
         &session_metadata,
@@ -1876,7 +1891,7 @@ pub fn send_cli_new_pane_action_with_command_and_cwd() {
         direction: Some(Direction::Right),
         command: Some("htop".into()),
         cwd: Some("/some/folder".into()),
-        floating: None,
+        floating: false,
     };
     send_cli_action_to_server(
         &session_metadata,
@@ -1913,7 +1928,7 @@ pub fn send_cli_edit_action_with_default_parameters() {
         file: PathBuf::from("/file/to/edit"),
         direction: None,
         line_number: None,
-        floating: None,
+        floating: false,
     };
     send_cli_action_to_server(
         &session_metadata,
@@ -1950,7 +1965,7 @@ pub fn send_cli_edit_action_with_line_number() {
         file: PathBuf::from("/file/to/edit"),
         direction: None,
         line_number: Some(100),
-        floating: None,
+        floating: false,
     };
     send_cli_action_to_server(
         &session_metadata,
@@ -1987,7 +2002,7 @@ pub fn send_cli_edit_action_with_split_direction() {
         file: PathBuf::from("/file/to/edit"),
         direction: Some(Direction::Down),
         line_number: None,
-        floating: None,
+        floating: false,
     };
     send_cli_action_to_server(
         &session_metadata,

zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_edit_action_with_default_parameters.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 1618
+assertion_line: 1937
 expression: "format!(\"{:?}\", * received_pty_instructions.lock().unwrap())"
 ---
-[SpawnTerminal(Some(OpenFile("/file/to/edit", None)), ClientId(10)), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]
+[SpawnTerminal(Some(OpenFile("/file/to/edit", None)), Some(false), ClientId(10)), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]

zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_edit_action_with_line_number.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 1650
+assertion_line: 1974
 expression: "format!(\"{:?}\", * received_pty_instructions.lock().unwrap())"
 ---
-[SpawnTerminal(Some(OpenFile("/file/to/edit", Some(100))), ClientId(10)), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]
+[SpawnTerminal(Some(OpenFile("/file/to/edit", Some(100))), Some(false), ClientId(10)), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]

zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_edit_action_with_split_direction.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 1682
+assertion_line: 2011
 expression: "format!(\"{:?}\", * received_pty_instructions.lock().unwrap())"
 ---
 [SpawnTerminalHorizontally(Some(OpenFile("/file/to/edit", None)), 10), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]

zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_pane_action_with_command_and_cwd.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 1889
+assertion_line: 1900
 expression: "format!(\"{:?}\", * received_pty_instructions.lock().unwrap())"
 ---
-[SpawnTerminalVertically(Some(RunCommand(RunCommand { command: "htop", args: [], cwd: Some("/some/folder") })), 10), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]
+[SpawnTerminalVertically(Some(RunCommand(RunCommand { command: "htop", args: [], cwd: Some("/some/folder"), hold_on_close: true })), 10), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]

zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_pane_action_with_default_parameters.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 1566
+assertion_line: 1826
 expression: "format!(\"{:?}\", * received_pty_instructions.lock().unwrap())"
 ---
-[SpawnTerminal(None, ClientId(10)), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]
+[SpawnTerminal(None, Some(false), ClientId(10)), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]

zellij-server/src/unit/snapshots/zellij_server__screen__screen_tests__send_cli_new_pane_action_with_split_direction.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-server/src/./unit/screen_tests.rs
-assertion_line: 1599
+assertion_line: 1863
 expression: "format!(\"{:?}\", * received_pty_instructions.lock().unwrap())"
 ---
-[SpawnTerminalVertically(None, 10), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]
+[SpawnTerminalVertically(None, 10), UpdateActivePane(Some(Terminal(0)), 1), UpdateActivePane(Some(Terminal(0)), 1), Exit]

zellij-server/src/wasm_vm.rs

@@ -394,6 +394,7 @@ fn host_open_file(plugin_env: &PluginEnv) {
         .senders
         .send_to_pty(PtyInstruction::SpawnTerminal(
             Some(TerminalAction::OpenFile(path, None)),
+            None,
             ClientOrTabIndex::TabIndex(plugin_env.tab_index),
         ))
         .unwrap();

zellij-utils/src/cli.rs

@@ -124,18 +124,18 @@ pub enum Sessions {
     #[clap(visible_alias = "ac")]
     #[clap(subcommand)]
     Action(CliAction),
-    /// Send actions to a specific session
-    #[clap(visible_alias = "c")]
-    Command {
+    /// Run a command in a new pane
+    #[clap(visible_alias = "r")]
+    Run {
         command: Option<String>,
         #[clap(short, long, value_parser, conflicts_with("floating"))]
         direction: Option<Direction>,
         #[clap(long, value_parser)]
         cwd: Option<PathBuf>,
-        #[clap(short, long, value_parser, default_missing_value("true"))]
-        floating: Option<bool>,
+        #[clap(short, long, value_parser, default_value("false"), takes_value(false))]
+        floating: bool,
     },
-    /// Edit file with default $EDITOR / $VISUAL in a specific session
+    /// Edit file with default $EDITOR / $VISUAL
     #[clap(visible_alias = "e")]
     Edit {
         file: PathBuf,
@@ -143,8 +143,8 @@ pub enum Sessions {
         line_number: Option<usize>,
         #[clap(short, long, value_parser, conflicts_with("floating"))]
         direction: Option<Direction>,
-        #[clap(short, long, value_parser, default_missing_value("true"))]
-        floating: Option<bool>,
+        #[clap(short, long, value_parser, default_value("false"), takes_value(false))]
+        floating: bool,
     },
     ConvertConfig {
         old_config_file: PathBuf,
@@ -201,7 +201,7 @@ pub enum CliAction {
     TogglePaneFrames,
     /// Toggle between sending text commands to all panes on the current tab and normal mode.
     ToggleActiveSyncTab,
-    /// Open a new pane in the specified direction [right|left|up|down]
+    /// Open a new pane in the specified direction [right|down]
     /// If no direction is specified, will try to use the biggest available space.
     NewPane {
         #[clap(short, long, value_parser, conflicts_with("floating"))]
@@ -210,8 +210,8 @@ pub enum CliAction {
         command: Option<String>,
         #[clap(long, value_parser)]
         cwd: Option<PathBuf>,
-        #[clap(short, long, value_parser, default_missing_value("true"))]
-        floating: Option<bool>,
+        #[clap(short, long, value_parser, default_value("false"), takes_value(false))]
+        floating: bool,
     },
     /// Open the specified file in a new zellij pane with your default EDITOR
     Edit {
@@ -220,8 +220,8 @@ pub enum CliAction {
         direction: Option<Direction>,
         #[clap(short, long, value_parser)]
         line_number: Option<usize>,
-        #[clap(short, long, value_parser, default_missing_value("true"))]
-        floating: Option<bool>,
+        #[clap(short, long, value_parser, default_value("false"), takes_value(false))]
+        floating: bool,
     },
     /// Switch input mode of all connected clients [locked|pane|tab|resize|move|search|session]
     SwitchMode { input_mode: InputMode },

zellij-utils/src/errors.rs

@@ -273,6 +273,7 @@ pub enum ScreenContext {
     SetFixedHeight,
     SetFixedWidth,
     ClosePane,
+    HoldPane,
     UpdatePaneName,
     UndoRenamePane,
     NewTab,
@@ -326,6 +327,7 @@ pub enum PtyContext {
     NewTab,
     ClosePane,
     CloseTab,
+    ReRunCommandInPane,
     Exit,
 }
 

zellij-utils/src/input/actions.rs

@@ -200,7 +200,7 @@ pub enum Action {
     /// If no direction is specified, will try to use the biggest available space.
     NewPane(Option<Direction>),
     /// Open the file in a new pane using the default editor
-    EditFile(PathBuf, Option<usize>, Option<Direction>, Option<bool>), // usize is an optional line number, bool is floating true/false
+    EditFile(PathBuf, Option<usize>, Option<Direction>, bool), // usize is an optional line number, bool is floating true/false
     /// Open a new floating pane
     NewFloatingPane(Option<RunCommandAction>),
     /// Open a new tiled (embedded, non-floating) pane
@@ -288,23 +288,29 @@ impl Action {
             } => match command {
                 Some(command) => {
                     let (command, args) = split_command_and_args(command);
+                    let cwd = cwd.or_else(|| std::env::current_dir().ok());
                     let run_command_action = RunCommandAction {
                         command,
                         args,
                         cwd,
                         direction,
+                        hold_on_close: true,
                     };
-                    match floating {
-                        Some(true) => Ok(vec![Action::NewFloatingPane(Some(run_command_action))]),
-                        _ => Ok(vec![Action::NewTiledPane(
+                    if floating {
+                        Ok(vec![Action::NewFloatingPane(Some(run_command_action))])
+                    } else {
+                        Ok(vec![Action::NewTiledPane(
                             direction,
                             Some(run_command_action),
-                        )]),
+                        )])
                     }
                 },
-                None => match floating {
-                    Some(true) => Ok(vec![Action::NewFloatingPane(None)]),
-                    _ => Ok(vec![Action::NewTiledPane(direction, None)]),
+                None => {
+                    if floating {
+                        Ok(vec![Action::NewFloatingPane(None)])
+                    } else {
+                        Ok(vec![Action::NewTiledPane(direction, None)])
+                    }
                 },
             },
             CliAction::Edit {

zellij-utils/src/input/command.rs

@@ -17,6 +17,24 @@ pub struct RunCommand {
     pub args: Vec<String>,
     #[serde(default)]
     pub cwd: Option<PathBuf>,
+    #[serde(default)]
+    pub hold_on_close: bool,
+}
+
+impl std::fmt::Display for RunCommand {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut command: String = self
+            .command
+            .as_path()
+            .as_os_str()
+            .to_string_lossy()
+            .to_string();
+        for arg in &self.args {
+            command.push(' ');
+            command.push_str(arg);
+        }
+        write!(f, "{}", command)
+    }
 }
 
 /// Intermediate representation
@@ -30,6 +48,8 @@ pub struct RunCommandAction {
     pub cwd: Option<PathBuf>,
     #[serde(default)]
     pub direction: Option<Direction>,
+    #[serde(default)]
+    pub hold_on_close: bool,
 }
 
 impl From<RunCommandAction> for RunCommand {
@@ -38,6 +58,7 @@ impl From<RunCommandAction> for RunCommand {
             command: action.command,
             args: action.args,
             cwd: action.cwd,
+            hold_on_close: action.hold_on_close,
         }
     }
 }

zellij-utils/src/input/unit/layout_test.rs

@@ -201,6 +201,7 @@ fn layout_with_command_panes() {
             children: vec![PaneLayout {
                 run: Some(Run::Command(RunCommand {
                     command: PathBuf::from("htop"),
+                    hold_on_close: true,
                     ..Default::default()
                 })),
                 ..Default::default()
@@ -226,6 +227,7 @@ fn layout_with_command_panes_and_cwd() {
                 run: Some(Run::Command(RunCommand {
                     command: PathBuf::from("htop"),
                     cwd: Some(PathBuf::from("/path/to/my/cwd")),
+                    hold_on_close: true,
                     ..Default::default()
                 })),
                 ..Default::default()
@@ -254,6 +256,7 @@ fn layout_with_command_panes_and_cwd_and_args() {
                     command: PathBuf::from("htop"),
                     cwd: Some(PathBuf::from("/path/to/my/cwd")),
                     args: vec![String::from("-h"), String::from("-v")],
+                    hold_on_close: true,
                     ..Default::default()
                 })),
                 ..Default::default()

zellij-utils/src/input/unit/snapshots/zellij_utils__input__layout__layout_test__layout_with_tab_and_pane_templates.snap

@@ -1,6 +1,6 @@
 ---
 source: zellij-utils/src/input/./unit/layout_test.rs
-assertion_line: 648
+assertion_line: 570
 expression: "format!(\"{:#?}\", layout)"
 ---
 Layout {
@@ -40,6 +40,7 @@ Layout {
                                                     command: "htop",
                                                     args: [],
                                                     cwd: None,
+                                                    hold_on_close: true,
                                                 },
                                             ),
                                         ),

zellij-utils/src/kdl/kdl_layout_parser.rs

@@ -177,6 +177,7 @@ impl<'a> KdlLayoutParser<'a> {
                 command,
                 args: args.unwrap_or_else(|| vec![]),
                 cwd,
+                hold_on_close: true,
             }))),
             _ => Ok(None),
         }

zellij-utils/src/kdl/mod.rs

@@ -590,12 +590,10 @@ impl TryFrom<(&str, &KdlDocument)> for PaletteColor {
 }
 
 impl TryFrom<&KdlNode> for Action {
-    // type Error = Box<dyn std::error::Error>;
     type Error = ConfigError;
     fn try_from(kdl_action: &KdlNode) -> Result<Self, Self::Error> {
         let action_name = kdl_name!(kdl_action);
         let action_arguments: Vec<&KdlEntry> = kdl_argument_values!(kdl_action);
-        // let action_arguments: Vec<&KdlValue> = kdl_argument_values!(kdl_action);
         let action_children: Vec<&KdlDocument> = kdl_children!(kdl_action);
         match action_name {
             "Quit" => parse_kdl_action_arguments!(action_name, action_arguments, kdl_action),
@@ -744,6 +742,7 @@ impl TryFrom<&KdlNode> for Action {
                     args,
                     cwd,
                     direction,
+                    hold_on_close: true,
                 };
                 Ok(Action::Run(run_command_action))
             },
@@ -1473,7 +1472,12 @@ impl RunCommand {
                 .collect(),
             None => vec![],
         };
-        Ok(RunCommand { command, args, cwd })
+        Ok(RunCommand {
+            command,
+            args,
+            cwd,
+            hold_on_close: true,
+        })
     }
 }
 

zellij-utils/src/shared.rs

@@ -62,7 +62,7 @@ pub mod colors {
     pub const GREEN: u8 = 154;
     pub const GRAY: u8 = 238;
     pub const BRIGHT_GRAY: u8 = 245;
-    pub const RED: u8 = 88;
+    pub const RED: u8 = 124;
     pub const ORANGE: u8 = 166;
     pub const BLACK: u8 = 16;
     pub const MAGENTA: u8 = 201;