kodegen_bash_shell/core/
terminal.rs

1//! Terminal control utilities.
2
3use super::{error, openfiles, sys};
4
5/// Encapsulates the state of a controlled terminal.
6pub struct TerminalControl {
7    prev_fg_pid: Option<sys::process::ProcessId>,
8}
9
10impl TerminalControl {
11    /// Acquire the terminal for the shell.
12    pub fn acquire() -> Result<Self, error::Error> {
13        let prev_fg_pid = sys::terminal::get_foreground_pid();
14
15        // Break out into new process group.
16        // TODO: jobs: Investigate why this sometimes fails with EPERM.
17        let _ = sys::signal::lead_new_process_group();
18
19        // Take ownership.
20        sys::terminal::move_self_to_foreground()?;
21
22        // Mask out SIGTTOU.
23        sys::signal::mask_sigttou()?;
24
25        Ok(Self { prev_fg_pid })
26    }
27
28    fn try_release(&mut self) {
29        // Restore the previous foreground process group.
30        if let Some(pid) = self.prev_fg_pid
31            && sys::terminal::move_to_foreground(pid).is_ok() {
32                self.prev_fg_pid = None;
33            }
34    }
35}
36
37impl Drop for TerminalControl {
38    fn drop(&mut self) {
39        self.try_release();
40    }
41}
42
43/// Describes high-level terminal settings that can be requested.
44#[derive(Default, bon::Builder)]
45pub struct Settings {
46    /// Whether to enable input echoing.
47    pub echo_input: Option<bool>,
48    /// Whether to enable line input (sometimes known as canonical mode).
49    pub line_input: Option<bool>,
50    /// Whether to disable interrupt signals and instead yield the control characters.
51    pub interrupt_signals: Option<bool>,
52    /// Whether to output newline characters as CRLF pairs.
53    pub output_nl_as_nlcr: Option<bool>,
54}
55
56/// Guard that automatically restores terminal settings on drop.
57pub struct AutoModeGuard {
58    initial: sys::terminal::Config,
59    file: openfiles::OpenFile,
60}
61
62impl AutoModeGuard {
63    /// Creates a new `AutoModeGuard` for the given file.
64    ///
65    /// # Arguments
66    ///
67    /// * `file` - The file representing the terminal to control.
68    pub fn new(file: openfiles::OpenFile) -> Result<Self, error::Error> {
69        let initial = sys::terminal::Config::from_term(&file)?;
70        Ok(Self { initial, file })
71    }
72
73    /// Applies the given terminal settings.
74    ///
75    /// # Arguments
76    ///
77    /// * `settings` - The terminal settings to apply.
78    pub fn apply_settings(&self, settings: &Settings) -> Result<(), error::Error> {
79        let mut config = sys::terminal::Config::from_term(&self.file)?;
80        config.update(settings);
81        config.apply_to_term(&self.file)?;
82
83        Ok(())
84    }
85}
86
87impl Drop for AutoModeGuard {
88    fn drop(&mut self) {
89        let _ = self.initial.apply_to_term(&self.file);
90    }
91}
kodegen_bash_shell/core/terminal.rs

kodegen_bash_shell/core/
terminal.rs
