Struct Console 

pub struct Console { /* private fields */ }

A handle to the virtual terminal, which restores whatever it changed on drop.

Nothing is changed by opening one. Call mute_keyboard and graphics_mode for that, and each remembers the mode it replaced so restore puts back exactly what was there rather than a guess at the default.

use denise_evdev::Console;

// A kiosk owns the screen and the keyboard for as long as this lives.
let mut console = Console::open()?;
console.mute_keyboard()?;
console.graphics_mode()?;

Developing over SSH, Console::open returns ConsoleError::NoConsole and the right response is to carry on without one — see open_if_present.

Implementations

impl Console

pub fn open() -> Result<Self, ConsoleError>

Opens the first of /dev/tty, /dev/tty0, /dev/console that is a real virtual terminal.

Returns ConsoleError::NoConsole when there is none — over SSH, under a terminal emulator, or in a container.

pub fn open_if_present() -> Option<Self>

open, but a missing console is None rather than an error.

For the common shape: mute if there is something to mute, and run normally on a development machine where there is not.

pub fn open_path(path: &Path) -> Result<Self, ConsoleError>

Opens a specific console device.

Fails with ConsoleError::NoConsole if the path opens but is not a virtual terminal.

pub fn mute_keyboard(&mut self) -> Result<(), ConsoleError>

Stops console keystrokes reaching the shell behind the UI.

evdev still delivers everything, so Denise’s own input is unaffected. This also disables Ctrl+Alt+F<n> VT switching, because the kernel discards those keys along with the rest — read the module docs before using it on a machine you cannot reach over the network.

Calling it twice is harmless: the mode remembered is the one from before the first call.

pub fn graphics_mode(&mut self) -> Result<(), ConsoleError>

Puts the console into graphics mode, so it stops drawing text over the display and stops blanking it.

DRM master already keeps fbcon off the scanout buffer in normal operation. This covers what master does not: console blanking on an idle panel, and the kernel repainting text after a VT switch or an oops.

pub fn restore(&mut self) -> Result<(), ConsoleError>

Puts back every mode this handle changed, and forgets them.

Runs automatically on drop. Call it directly to hand the console back early — before spawning a shell, say — or to see the error, which Drop has nowhere to report.

pub fn keyboard_mode(&self) -> Result<u32, ConsoleError>

The current keyboard translation mode: one of K_RAW, K_XLATE, K_MEDIUMRAW, K_UNICODE or K_OFF.

pub fn screen_mode(&self) -> Result<u32, ConsoleError>

The current screen mode: KD_TEXT or KD_GRAPHICS.

Trait Implementations

impl AsFd for Console

fn as_fd(&self) -> BorrowedFd<'_>

Borrows the file descriptor.

impl Debug for Console

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for Console

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.